Nigel Farage is being lined up as leader of a new pro-Brexit party if Britain’s departure from the European Union is delayed beyond 29 March.

The former Ukip leader said he had offered his enthusiastic support to the Brexit party after being sounded out as its potential leader.

Catherine Blaiklock, Ukip’s former economics spokeswoman, confirmed she had applied to register the party with the Electoral Commission on 11 January and that it would be ready to fight any snap general election or the local elections across England in May.

She told the Guardian on Sunday: “I think people feel treason has been committed. It’s democracy. It wouldn’t matter whether leave had won by a single vote – it’s a first-past-the-post system.”

Blaiklock said the party was aiming to attract the 17.4 million people who voted to leave the EU in June 2016 and to win over defectors from the Conservatives, Labour and Ukip.

Ukip has suffered the mass resignation of more than a dozen senior party figures, including Farage, in recent weeks in protest at its anti-Islam focus under its leader, Gerard Batten.

Farage told the Sun on Sunday: “There is huge demand for a party that’s got real clarity on this issue. You can see and hear the frustration welling up out there. It’s clear the political elite want to stop Brexit in its tracks and the prime minister doesn’t have the strength or inclination to see this through.

“I’ve been watching events with growing dismay – I’m not the only one. Now we are putting them on notice that if Brexit doesn’t happen on 29 March we are not prepared to stand by and do nothing.”

Farage added: “If the government goes back on its word and betrays the millions of people who voted for Brexit then we need a party prepared to stand up and fight for it. I’m fully prepared for article 50 to be extended or revoked and if that happens, I will re-enter the fray.”

Blaiklock, who quit Ukip a week after Farage in December, declined to say whether the fledgling Brexit party had approached other senior Ukip figures about defecting – or whether it had lined up any wealthy donors.

Arron Banks, the businessman being investigated by the National Crime Agency over his role in the Brexit referendum, has repeatedly expressed support for a “Ukip 2.0” with Farage as its leader.

The Electoral Commission confirmed the Brexit party had applied to be registered. Its website said it would aim to decide on new political party registrations by 1 April – weeks before the local elections in England and Northern Ireland.

Blaiklock, an Oxford University-educated businesswoman, described Farage as “an international superstar” and said that, pending approval by the commission, the new party would be ready to fight elections or a second referendum should article 50 be extended beyond 29 March.

“A million more people voted for leave than remain,” she said. “What you’re saying is that it doesn’t matter what the majority is, democracy doesn’t count. You’re destroying the system. Never in a general election has anybody ever had a revote. If you take London out, leave won by 11% – not just a few per cent”.