>>342 Ok I will try. No guarantee that other Brits on here will quite agree but here goes.
UKIP - usually accepted to be most far right party. Wants end to participation in EU, end to immigration (often thought to be appealing to covertly or openly racist views though they deny this), end to Human Rights Act, repeal of equal rights legislation for women, POC, disabled etc, support for broadening gun laws. Large popular support when counted nationwide but one MP due to vagaries of political system (votes split across hundreds of MP elections so almost no wins. I mention them first but they are regarded as a marginal party - extreme views, some grassroots support (like DT but much less successful in the event).
Conservative - very broadly equivalent to Republican. But a lot less right wing. For example: No support for repealing abortion laws. No support for broadening gun laws and indeed legislated against handgun ownership in the 80s. Supports and brought in legislation for gay marriage in last Parliament.
Labour - very broadly equivalent to Democratic Party. But a lot more left wing eg some want to end nuclear deterrent and in the 70s there was 99% tax for highest earners. Bernie Saunders would be moderate in the Labour Party. New leader after a fairly crushing defeat in the last election when it was widely predicted they would win. He is called Jeremy Corbyn - little political experience as a front bencher (ie holding a shadow cabinet post). Another expression of grassroots discontent, from the other end of the policitcal spectrum - he is not widely supported by other Labour MPs.
Liberal Democrats - hard to place. Theoretically liberals would be between labour and conservative historically. The party originated in the 19th century as an alternative to Tories (conservative) and Whig (not equivalent to labour but more left wing). Recently it tried to position itself to the left of Labour. Was decimated in the last election and now only has 9 MPs. Ironically UKIP got more votes I think.
Broadly speaking we have a similar structure but it is all shifted to the left.We had a couple of Communist MPs during WW2. There is a great Monty Python sketch explaining the US system to the British whic says "The Republican Party: this is equivalent to the Conservative Party. The Democratic Party: this is equivalent to the Conservative Party."