Over 1 million sign petition demanding 2nd Brexit referendum in UK

Over a million people have signed a petition in the UK calling for a second referendum over the country's EU membership following the shock Brexit vote.

The petition will now have to be discussed in the British Parliament, having crossed 100,000 signatures required to trigger a debate in the House of Commons.

The UK voted to leave the EU by 52 to 48 per cent in Thursday's referendum but the majority of voters in London, Scotland and Northern Ireland backed the Remain side in a 72 per cent turnout.

The petition passed the million mark this morning, with votes most concentrated in London, Brighton, Oxford, Cambridge and Manchester.

The petition started by William Oliver Healey reads, "We the undersigned call upon Her Majesty's Government to implement a rule that if the Remain or Leave vote is less than 60 per cent based a turnout less than 75 per cent there should be another referendum."

The website of the parliamentary petition at one point crashed due to the number of people adding their names to the call for another referendum.

It remains unclear if a change to the rules demanded by the petition were to come into force and inserted into UK legislation, could be applied retrospectively.

After the Scottish independence referendum in 2014, the 45 per cent of voters who lost started a similar campaign for another vote.

A second referendum in Scotland is now likely after First Minister Nicola Sturgeon said there had been a "significant change" to the circumstances of the original poll and that it should be back "on the table".

A parallel petition calling for London mayor Sadiq Khan to declare 'Londependence', or the British capital an independent state, after the UK voted to quit the EU has also been signed by thousands of people.

The petition's organiser James O'Malley, said the capital was "a world city" which should "remain at the heart of Europe".

An overwhelming 60 per cent of Londoners had voted to remain in the EU, in stark contrast to other English cities like Birmingham and Coventry.