First past the post is bad for the people

The purpose of the state is to serve the people otherwise there would be no reason to have a state. The people do not exist to serve the state. And so then it makes sense to use democracy to make sure the state is accountable to the people and that the people are able to remove unpopular governments. Within the context of the existence of a state democracy makes sense and is consistent with natural rights. Democracy is not criminal but with a two-party fptp system voters who support democracy and proportional representation are ignored which means that they are being punished. The fptp system punishes people who support the smaller parties and those who support (pr and) democracy. But since the smaller parties are not by definition criminal the fptp system is punishing innocent people and innocent voters. Unless people and voters are to be presumed guilty then the first past the post system is punishing innocent people by excluding them and their votes from government.

If there is a state then not to be democratic is a crime and fptp is not democratic.

Proportional representation is more direct than fptp

It is better to have direct democracy than to have representative democracy because (we assume) the people know what is in their own interests. If direct democracy is not a good idea then democracy itself is not a good idea and if we have a state it will be totalitarian. If in the context of a state democracy is good then direct democracy must be the best form of democracy.

The circumstances in which democracy tends not to be direct are when we have constituency seats which have only one winner. If there are multiple winners then generally voters get what they want and so then we can describe this as approximating to direct democracy. When there are few winners (even only one winner) then people vote tactically and we end up with representative democracy. Proportional representation approximates to direct democracy and first-past-the-post is the most extreme form of representative democracy.

Direct democracy is the best form of democracy and proportional representation provides something very close to this but without the requirement for frequent referendums.

First past the post is a state error

The purpose of democracy and elections is to enable the people to choose their own representatives. We do not have a democratic system if people feel unrepresented but the first-past-the-post system tends to encourage so-called tactical voting. With a fptp system there is only one winner which means that voting for candidates which are not expected to do well is likely a wasted vote. For the electoral system to work well (one presumes) we require that all voters are able to be represented and that tactical voting is kept to a minimum. So a well-designed system is one which reduces tactical voting and hence provides proportional representation. If the system is not proportional it has at least partially failed in its purpose.

The state has made an error if it has chosen to use a less than proportional system and then fptp is an error by the state.

The state has an obligation to be helpful to the people

In order for the state to have legitimacy it must be accountable to the people since otherwise it might be unpopular. The state has an obligation to be helpful to the people which implies democracy. We know that if the state has been democratically elected that it is accountable and useful to the people. But if the state seeks democratic legitimacy it must use the most democratic means of election possible which is proportional representation. If the state fails to use pr then it is not being fully democratic and it might be failing in its obligations to the people. The state must be democratic and if the state fails to see this then it is in denial. The state is in denial if it fails to realise its obligation to be fully democratic and to use proportional representation.

The state is in denial if it doesn't use proportional representation.

Only the left can change first past the post

It is only the political left who are able to change the voting system because it is only they who get elected.

The first-past-the-post system requires of voters on both sides to be loyal to the main party on each flank. For the left this is easy since leftist voters tend to be loyal but for the right this is more of a problem because their voters are not so interested in being loyal to the main party. For them (the right) it is much less of a contradiction to vote for one of the smaller parties. This means that the left generally prevail in a fptp election. Because the left are generally in power when fptp is used it is only they who can change the system. The party of the right could change it if they get into power but they are always excluded because the fptp system favours the (political) left. It is only the left who can change the fptp system and replace it with a system of proportional representation because the right are never in power when fptp is used.

Fptp is fine if everyone likes one of the main parties

If people genuinely want to vote for one of the big and established parties then first-past-the-post is not a problem. If no one wants to vote for a party which is not one of those protected by fptp then no one will see a problem with the system. It is only if people are inclined to vote tactically that there might be a problem with first-past-the-post. We can think of fptp as a fully-proportional system if almost everyone wants to vote for one of the main parties. It is only if some people don't like either that fptp is oppressive. If people are voting tactically under fptp then the system is oppressing their democratic rights and imposing more government on them than they want. We can assume to oppress democracy is to impose more government on the people than they want otherwise there would be no reason to have democracy to begin with. (It is to prevent communism that we have democracy.) So tactical voters are anti-government voters who are being ignored when using the fptp system. If there is tactical voting in a fptp system (and some people dislike both of the main parties) then fptp is being oppressive to democracy and therefore oppressive to freedom. First-past-the-post is anti-freedom if some people are inclined to vote tactically. Fptp is neutral with regard to freedom if almost no one is offended by both of the main parties (most people can accept at least one of them). Tactical voters are liberal (libertarian) so then fptp is arrogant (anti-democratic) and oppressive. First-past-the-post is democratic only if most of the voters are satisfied with at least one of the (two) main parties. If some people don't like both of the main parties (voting tactically or for smaller parties) then fptp imposes more government on the voters than they want (unless democracy is authoritarian). Fptp is authoritarian unless everyone likes at least one of the main parties.

There is no reason for a good state to reject pr

If the state is bad then democracy is good because it imposes a constraint on the state. If the state is an objective good then there will be no need for democracy because the state will always know what is in the best interests of the people. Assuming the people know what is good for them democracy is good and a good state will have no reason to reject democracy. It is only if the people do not know what is good for them that democracy threatens a good state. Anti-democratic states are either bad or know more than their people.

If we assume that the state doesn't know more than its people then there is no reason for a good state to oppress democracy and reject proportional representation. Only if the state is objectively bad or knows more than its people would there be a reason (for it) to promote first-past-the-post but since we have no way to know that the state knows more than the people (and that in general people know what is in their own interests) only a bad state would promote first-past-the-post.

If an anarchist is someone who rejects all state (for them all states are bad) then it is perfectly natural (for them) that a state might promote fptp because for the state to be bad is not unexpected. State-promotion of fptp is not shocking to an anarchist because for them it is consistent for the state to reject democracy.

The Labour party and the Tories have shared interests

The nature of the first-past-the-post (fptp) voting system is that (at least initially) it tends to result in a two-party system. But over time we see that it is more favourable to the party of the left because voters on the right are more inclined to reject a monopolistic party (they want more choice). So whilst (in the UK) the Tory party might consider themselves to be beneficiaries of the fptp system in fact their voters lose out. Assuming voters on the right are more interested in policies than parties it is clear that fptp is detrimental to their interests.

First-past-the-post is very helpful to Labour (more so than to the Tories) in which case Tory support for fptp can be interpreted as a subsidy for the Labour party. The Tories could easily damage the Labour party by advocating a form of proportional representation but since they don't we deduce that the Tories support Labour. Antagonistic parties would not support each other in this way and so then it is clear that the Labour party and the Conservative party have shared interests.