So, it’s finally happened: after months of speculation, Labour’s outspoken centrist MPs have left the party, saying that the Labour leadership no longer shares their values.

The MPs will sit in the House of Commons as The Independent Group and a website and social media channels were up and running by the time the seven took to the stage.

What does this mean for Labour? Firstly, the last time Labour split on this scale, when the Gang of Four formed the SDP in 1981, it ushered in eighteen years of Tory governments because the anti-Conservative vote was split.

Labour’s leadership will be acutely aware that this will make it harder for Jeremy Corbyn to enter Number 10. With both parties neck and neck in the polls, every vote and every seat in the Commons will count.

Secondly, an independent centre grouping in the Commons will provide a platform for dissent. The group will no longer be subject to the threat of trolling of deselection by Momentum because they have effectively deselected themselves.

This means they will be free to say whatever they like on policy issues ranging from national security to public services, but focused on Brexit – the issue that hurts Corbyn most amongst party members and left-of-centre voters. The group will also be vocal on internal party matters such as anti-Semitism where the bullying campaign against Luciana Berger in Liverpool Wavertree is known to worry Corbyn’s inner circle, simply because of how bad it looks to the public.

The group will sit as a formal bloc within Parliament with spokespeople and structures and if they are entitled to ‘short money’ they will receive public funding. Donations are also to be published. The key question is whether or not more MPs will join them and to what extent they can lay down roots across the country. Chuka Umunna made a clear call to the British public to join the group at the end of his statement.

This brings us to the People’s Vote Campaign, who announced over the weekend that there will be a mass demonstration on March 23rd. This will provide a national platform for members of the Group and if it attracts similar numbers to the demonstration last Summer you can start to see what a new national Party might look like.

The official Labour response has been that Jeremy Corbyn is disappointed to see them go. The unofficial response has been that Labour are better off without them. Twitter trolls will be out in force, led by Corbyn’s outriders in the media. Momentum have accused them of creating a ‘spoiler Blairite Party’ with the objective of splitting Labour’s vote in Tory marginals.

Vince Cable has issued a statement saying the Liberal Democrats would be “engaging in talks” to advance of a second referendum. Their network of councillors could be crucial in the formation of any new national centrist party. All eyes now will be on what the moderates in the Conservative party might be tweeting. By positioning themselves as The Independent Group it leaves the door open for people like Anna Soubry or Dominic Grieve who have worked closely with Chukka Umunna in the campaign for a second vote.

The seven Independent MPs are Chuka Umunna (Streatham), Luciana Berger (Liverpool Wavertree), Anne Coffey (Stockport), Gavin Shuker (Luton North), Mike Gapes (Ilford South), Chris Leslie (Nottingham East) and Angela Smith (Penistone and Stocksbridge).