Hundreds of thousands of supporters of the European Union have marched through London in the biggest demonstration against Brexit in the UK.

Supporters of a so-called "People's Vote" are demanding the British government hold a referendum on the terms of the final exit deal.

However, the prime minister is, thus far, refusing and the opposition Labour Party seems reluctant to force the issue.

There's growing concern the UK may leave the EU next March without a deal.

Al Jazeera's Paul Brennan reports from Central London.

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