Chuka Umunna, Heidi Allen and Chris Leslie at the launch of the Change UK European election campaign in Bristol

A leading Change UK activist has quit the party, claiming that it is “riddled with distrust” and letting down those who believed it heralded “a new kind of politics”.

Dan Heley, who helped to develop the grassroots movement that backed Change UK, said he had hoped the party was going to be “the fresh face of politics that society was crying out for”.

Instead it had resorted to old-style political manoeuvring, power struggles and nepotism, leaving volunteers feeling “dejected and regretful”, he said.

The Independent Group was formed in February by eight former Labour MPs and three Tories, before registering as a political party, Change UK, this month.

Mr Heley founded The Independent Group Activist Network of more than 140 voluntary groups nationwide. Heidi Allen,