John McDonnell praises Momentum role in Labour election campaign
John McDonnell has praised the "remarkable impact" controversial campaign group Momentum made on Labour's local election campaign.
In an email to activists, the Shadow Chancellor also urged them to join the pro-Jeremy Corbyn organisation, which has come in for heavy criticism from moderate Labour MPs.
Labour lost 28 local council seats last Thursday, slipped back slightly in Wales and came third in Scotland behind the SNP and Conservatives.
But Mr McDonnell insisted they showed Labour has "a firm base to build on" - and gave Momentum much of the credit for the party's performance.
He said: "On behalf of the Labour party and its leadership, I would like to express my sincere thanks to each and every Momentum member and supporter who played a part in our tremendous effort to secure Labour wins in the elections last week.
"We held our own or advanced in key marginal councils with Tory MPs, including: Worcester, Redditch, Derby, Ipswich, Norwich, Harlow, Crawley, Southampton and Hastings. Not to mention the four excellent Labour mayors we've elected in London, Bristol, Liverpool and Salford.
"I know that Momentum groups have been particularly active in many of these areas, and indeed elsewhere, so thank you for the remarkable impact you have made.
"What is perhaps most heart-warming of all, is the knowledge that Momentum groups played a key role in mobilising many new and less experienced activists. Jeremy’s leadership inspired many tens of thousands of people to join Labour and get involved in politics for the first time, and now that fresh energy lives on in Momentum."
Mr McDonnell added: "We have a solid Labour base in England and Wales, but there is much more work to be done. If you’re not already, I would urge you join the Labour Party and to join Momentum as well.
"Becoming a member of Momentum will enable to you to be part of and shape a growing network of people and groups who are committed to building a more democratic and equal society and see a Jeremy-led Labour Party in government."
But the email is sure to infuriate many Labour MPs at a time when Mr McDonnell himself has called on the party to unify behind Mr Corbyn's leadership.
In March, Stella Creasy accused Momentum of trying to deselect Labour MPs not loyal to the leader - something the group has denied.
Deputy Labour leader Tom Watson has also called them a "rabble", while Tom Blenkinsop called for them to be banned.
One backbencher told PoliticsHome: "This email from John McDonnell is quite remarkable. Why is he encouraging people to join Momentum? It's a divisive act at a time when we're supposed to be coming together."