The prime minister unexpectedly called a snap general election for June 8th. Nearly 1 million extra people have registered to vote since the election was called. See: http://www.bbc.co.uk/news/election-2017-39837917 People who are British, Commonwealth or Irish citizens are entitled to vote for MPs in general elections
Lambeth sent out poll cards last week to everyone who registered to vote a while ago. If you registered recently you should get a poll card soon. But the easiest way to make sure you are registered to vote is to register or re-register online at https://www.gov.uk/register-to-vote It takes just a few minutes and you just need your NI number.
Monday 22nd May is the deadline to register in time for the June 8th general election.
If you would prefer to vote by post you must get a signed form to Lambeth council, Olive Morris House SW2 1RD by 5pm on Tuesday 23rd May. The deadline to apply for a proxy vote is 5pm on Wednesday 31st May.
For more details see: https://www.lambeth.gov.uk/elections-and-council/elections/elections-guide
Helen Hayes was elected MP for Dulwich & West Norwood in 2015 and Helen is standing again on June 8th : http://www.helenhayes.org.uk/about