James Carver, who quit as Ukip‘s foreign affairs spokesman on April 25 in protest at leader Paul Nuttall’s plans to ban the burka, said he had made the decision “some time ago”.
The Worcester-based West Midlands MEP said he wanted to focus on voting to get Brexit through the European Parliament.
Mr Carver contested the Stourbridge seat at the last general election in 2015, coming third with more than 7,000 votes.
His announcement comes as early local election results showed Ukip had lost all its council seats in Lincolnshire overnight.
The shire is a key battleground for the party, after a majority of the county’s voters backed leaving the EU in last year’s referendum, with Mr Nuttall declaring he would be running as a candidate for Boston and Skegness in the poll on June 8.
Mr Carver said: “With Brexit going on in the European Parliament, people underestimate the importance of the parliament and the relevance of MEPs in the Brexit process – and I’ll be voting on the final Brexit vote.”
He added: “With regards to my resignation, I thought it might it very difficult to stand on our party’s manifesto.
“This allows me instead to go to support other candidates nationally.”
He said it was “an unhappy coincidence” that his decision not to run was coming out as initial local election results also showed a party wipe-out in seats in Hampshire and Essex.
Mr Carver added: “I thought I’d made it clear some time ago, I wouldn’t be standing (in the general election).”
Of Mr Nuttall, he said he was “absolutely committed to his leadership”.
Speaking about the party’s local election fortunes, Mr Carver added that it was always going to be “a difficult night” and that Ukip voters who deserted the Tories in 2015 were returning to the Conservatives.
He said: “We got 4.2 million votes at the last general election and the Tories won.
“We were taking votes from the Tories, but those votes are returning to the Tories.
“It’s clear our support is coming now largely from…