Ukip Wales leader Neil Hamilton will contest the seat previously held by Paul Flynn following the death of the veteran Labour MP.

The Newport West by-election will be held on April 4 and will be the first electoral test following the UK’s exit from the EU on March 29.

Ukip announced Mr Hamilton’s candidacy on Monday afternoon, nearly 22 years after he was defeated at the 1997 general election.

Mr Hamilton, who was the Conservative MP for Tatton between 1983 and 1997, said his election would send a “lightning bolt to Westminster”, and accused the Tories and Labour of “betraying” Brexit, which Newport voted for by 56% to 44%.

He said: “My parents were married in Rogerstone. My mother’s family lived in Castleton 200 years ago and moved to Risca when the coal industry developed. I was born in the old county of Monmouthshire and lived in Blackwood as a boy.

“The Conservatives and Labour are jointly betraying Brexit. May and Corbyn are determined to stop us leaving the EU on March 29. Labour now wants a second referendum, to try and reverse the last People’s Vote.

“The Lib Dems and Plaid Cymru are total Eurofanatics. They think they know best. This by-election is a chance to poke them all in the eye.

“Newport voted ‘Leave’ by a large majority, but the political establishment refuses to listen. Ukip is the only party committed to an immediate, clean Brexit.

“On April 4, Newport West can deliver a lightning bolt to Westminster and Cardiff Bay and make the political elite listen to the People. Newport can make Brexit happen.”

Mr Hamilton said Wales was the poorest part of the UK following devolution, and promised to put more money into the pockets of ordinary people – strict immigration control to combat wage-depression, cheap food by scrapping EU import taxes, cheaper electricity and gas by scrapping “green taxes”, ending the BBC TV licence fee, slashing non-humanitarian foreign aid and abolishing VAT on basic necessities.

Ukip leader Gerard Batten said: “Neil Hamilton is an enormously experienced campaigner who has been fighting to keep Britain out of the EU since 1967. Ukip is taking this by-election very seriously, and we are committing significant resources to it.

“If the United Kingdom does not leave the European Union at 11pm on March 29, Remainer MPs in Leave majority seats will be fearful for their political futures and Ukip is ready to challenge the political establishment in every corner of the country starting with Newport.”

Hamilton currently represents the Mid and West Wales region in the Welsh Assembly.

Long-serving Mr Flynn died aged 84 earlier this month after representing the South Wales constituency for 32 years.

He retained the seat at the 2017 general election with a 5,658 majority over the Conservative candidate.