Labour’s most senior figure to date has switched her allegiance to UKIP, in a further blow to Ed Miliband as he faces a almost vertical climb to win the General Election in May.

Harriet Yeo, who was chairman of Labour’s National Executive Committee between 2012 and 2013, has become disillusioned with the Labour leader’s inability to support a referendum on Britain’s membership of the European Union, the Telegraph reports.

In her first tweet of 2015, Mrs Yeo said she would ‘campaign flat out’ for a referendum on EU membership.

Speaking to Breitbart London, Mrs Yeo said that at the time she wrote the tweet she “had decided at that stage to stay in the Labour party but I decided that actually, if I wanted to really campaign, the best place to do it was by saying that UKIP were the party to vote for.”

Speaking about the reaction she has had to her comments today, Mrs Yeo said, “The public are less and less tribal and that is where we have this complete divorce between politics and people. There are fewer people in political parties these days for that reason.”

The party responded to the news by denying Mrs Yeo was an important figure in the party, despite her election to the senior position. There are suggestions that several Labour MPs are considering defecting, including rumours of a female MP who has met with UKIP’s leader.

Mrs Yeo, whose daughter Angharad defected to Nigel Farage’s party in January 2013 and stood for Kent County Council, was elected by the membership to the board which governs the Labour party.

Miss Yeo, who was also a Labour supporter, said she defected “because Labour does not listen nationally or locally and they were failing their voters.”

“Labour do not represent the lower waged nor do they care for the South East,” she told Breitbart London. “David Miliband said at a meeting I attended that the South East is ignored due to the party not having a large enough share of the vote.”

Her mother has also been president of the Transport and Salaries Staff’s Association union and has been involved in the trade union movement for more than 20 years.

While she has resigned her Labour party membership, she has not officially joined UKIP although Breitbart London can exclusively reveal that she has previously held meetings in Autumn of last year with party leader Nigel Farage to discuss what role she could play in the party.

Mr Farage said he was “delighted that UKIP can now count upon the support of such respected figure as Harriet Yeo.”