Million march against Brexit

Brexit march
Polls show falling support for Brexit. Photo credit: Reuters

Demonstrators from around Britain have marched in London to call for a second referendum on the country's departure from the EU, as a petition calling for the whole Brexit process to be scrapped shot past the 4 million mark.

Prime Minister Theresa May is strongly against both options but currently faces a deadlock both with parliament, which refuses to endorse her plan for Brexit, and with Brussels, which refuses to alter the deal it negotiated with May over the past two years.

A similar rally in October attracted up to an estimated 700,000 people.

Campaigners marched from Park Lane to Parliament Square from midday on Saturday, followed by a rally in front of parliament.

London Mayor Sadiq Khan from the opposition Labour Party was at the head of the march, and tweeted: "We are the people - and when it comes to Brexit we want a say over our future."

"Whether you voted for remaining in the European Union or leave, whichever political party you support, I think we can all agree the path we're being forced down is not in the national interest," he said at the march. "It will make us poorer, not richer; it'll make us weaker, not stronger."

Scottish National Party leader Nicola Sturgeon said she was "proud to speak" at the march.

May has repeatedly dismissed calls for a second referendum despite parliament so far failing to agree on a deal for Britain to exit the European Union.

Parliament was set to be given a third chance at voting on her deal with Brussels in the coming week but in a letter to MPs, May said this might not happen after all because of a lack of support.

In the letter, May tried to increase the pressure on MPs, saying that unless her deal is passed, Britain may be facing a longer Brexit delay and may have to participate in the EU elections in May.

EU leaders and the British premier this week agreed to a delay, averting the prospect of Britain crashing out of the European Union on March 29.

Brussels offered London "an extension until 22 May 2019, provided the withdrawal agreement is approved by the House of Commons next week".

If it is not approved, EU leaders agreed to an extension until 12 April 2019, calling on London to "indicate a way forward before this date" for them to consider.

Meanwhile, a petition calling for Britain to stay in the EU had garnered 4.5million signatures by Sunday morning (NZ time).

The fast sign-up rate crashed the website on Thursday.

Downing Street suggested that May is likely to ignore the petition, saying she "will not countenance revoking Article 50" which governs Brtain's departure from the EU.

The 77-year-old woman who started the petition told BBC News she's received death threats.

Reuters / Newshub.