'Thousands' of people have travelled from Wales to take part in an ant-Brexit march in London, according to a Welsh MP.
Stephen Doughty, MP for Cardiff South and Penarth, posted a picture of him on his way to London and claimed he was joined by 'thousands' of other Welsh people.
Demonstrators have flooded the streets of central London as they marched on Parliament to demand the public are given a final say over Brexit.
Organisers claimed there was a turnout of around one million, which they said made it one of the biggest protests in British history.
An online petition demanding the Government stops the Brexit process had topped four million signatures by Saturday morning.
It is now the most popular ever submitted to the Parliament website, moving ahead of a 2016 petition calling for a second EU referendum.
Marching bands, music, whistles, chants and cheers provided a noisy backdrop to the march.
Demonstrators wore blue and yellow berets and flew large EU flags above the crowd as the march slowly made its way to Parliament Square.
Placards bore messages urging the Government to "revoke article 50" and for Brexit to be put to the people.
The size of the crowd saw people spill over into the capital's side streets and some underground trains were not stopping at Green Park station.
Mariella Frostrup and Richard Bacon, who were hosting a rally in Parliament Square, told the crowds an initial count showed the amount of people taking part in the march had topped one million.
Scottish First Minister Nicola Sturgeon, former deputy prime minister Lord Heseltine and London mayor Sadiq Khan are also expected to take the stage.
Other speakers will include former Conservative cabinet minister Justine Greening and ex-attorney general Dominic Grieve, former Tory turned independent MP Anna Soubry, Lib Dem deputy leader Jo Swinson, Green Party MP Caroline Lucas and SNP Westminster leader Ian Blackford.
The London march coincides with pro-Brexit campaigners continuing their long hike from the North East to the capital. Former Ukip leader Nigel Farage re-joined the March to Leave when it set off from Linby, near Nottingham, on Saturday morning.
Saturday's demonstrations follow EU leaders agreeing to delay Brexit to give Prime Minister Theresa May a final chance to get her deal through Parliament.