Millions of Britons have defied the wet weather to queue in torrential rain and even wade through deep water to vote in today's historic EU referendum as a final poll revealed the result is on a knife edge.

Several polling stations were closed in London because of floods as Britain was finally having its say on whether to stay in the EU or cut our ties with Brussels after a gruelling 10-week campaign.

Thundery showers caused chaos across London and the south of England overnight and could potentially push the result towards a Brexit because polling data is clear that Leave voters are less likely to be put off by the bad weather than Remain voters.

Today long queues snaked down the road from many polling stations as voters rushed to have their say when the polls opened at 7am,

David Cameron voted in Westminster with his wife Samantha this morning with the final EU referendum polls making the contest too close to call.

An exclusive survey for the Daily Mail and ITV News, gave the Remain camp a lead of six points, by 48 per cent to 42 per cent – but 11 per cent of electors said they were still undecided. 

The In camp are ahead of Leave by 52 per cent to 48 per cent, according to an Ipsos Mori survey for the Evening Standard this afternoon. To add further uncertainty to the outcome, 12 per cent of those polled said they could switch sides as they head for the polling booth.

But according to an online poll by Populus the Remain campaign is at 55 per cent compared to Leave on 45 per cent.

Today's EU vote is a historic day for Britain because it is only the third nationwide referendum ever to take place in the UK. A record 46.5million are registered to vote. 

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Willing to wait: Queues formed outside polling stations across many parts of the UK today people had their say despite terrible weather across swathes of the south, including here in West Hampstead, London