Oliver Dowden has resigned as chairman of the Conservative Party after it suffered two by-election defeats, saying in a letter to Prime Minister Boris Johnson that “someone must take responsibility”.

In Tiverton and Honiton the Liberal Democrats overturned a 24,000 Tory majority to win, while Labour reclaimed Wakefield.

The contests, triggered by the resignation of disgraced Tories, offered voters the chance to give their verdict on the Prime Minister just weeks after 41% of his own MPs cast their ballots against him.

Mr Dowden, who was due to appear on the morning media round for the Government on Friday (June 24), said in his letter to the PM the by-elections “are the latest in a run of very poor results for our party”.

Bicester Advertiser: Simon Lightwood celebrates winning in Wakefield (PA)Simon Lightwood celebrates winning in Wakefield (PA)

“Our supporters are distressed and disappointed by recent events, and I share their feelings.

“We cannot carry on with business as usual. Somebody must take responsibility and I have concluded that, in these circumstances, it would not be right for me to remain in office.”

The MP ended his letter by saying: “I want to emphasise that this is a deeply personal decision that I have taken alone.

“I will, as always, remain loyal to the Conservative Party.”

A dramatic swing of almost 30% from the Tories to the Liberal Democrats saw Richard Foord secure a majority of 6,144 in Tiverton and Honiton.

Meanwhile in Wakefield, Simon Lightwood was elected with a majority of 4,925 on a swing of 12.7% from the Tories to Labour.

The previous Wakefield MP Imran Ahmad Khan quit after being found guilty of sexually assaulting a 15-year-old boy – a crime for which he was jailed for 18 months.