Nigel Farage is to give serious consideration to contesting the Newark byelection that was triggered after the former Conservative frontbencher Patrick Mercer resigned his seat before the publication of a report that will call for his suspension from parliament for six months.

The Ukip leader, who would strengthen his case to be included in the general election television debates if he were elected an MP, said winning a parliamentary seat would burst the dam of British politics.

"We are very keen to get our first MP in Westminster because once that happens then the dam will have burst," he told ITV News. "So I am going to think very hard about this over the next few days."

But Farage, who declined to stand in the Eastleigh byelection last year despite standing in the seat nearly 20 years earlier, gave himself some leeway for the byelection, to be held after the European parliamentary elections on 22 May. The Ukip leader, who will have clocked that his party came a distant fourth in Newark in 2010 with 3.8% of the vote, told the BBC: "What I've got to work out is, is it the right seat for me. My reservation in my mind is I haven't particularly got connections with the local area."

Farage will be hugely tempted to stand in the byelection that could take place after a Ukip victory in the European elections. His presence at Westminster would act as a jolt to the Conservative party and would embolden eurosceptic right wing Tories who want David Cameron to harden up his negotiating plans ahead of an in/out referendum on Britain's EU membership by 2017.

A Ukip victory in the byelection would also boost the party ahead of the general election by making it all but impossible to exclude Farage from any general election television debates. Broadcasters have advised that a Ukip victory in the European elections, coupled with an elected presence at Westminster, would meet the conditions to include Farage in the debates.

But Farage will be highly cautious. Mercer held Newark with a 16,152 majority after securing 53.9% of the vote.

He paved the way for a byelection by pre-empting the Commons standards committee, which will recommend on Thursday that he should be suspended for six months. The committee has decided on a particularly severe punishment after Mercer allegedly asked questions in parliament in exchange for thousands of pounds from a fake lobbying firm.

The former army officer, who resigned the Tory whip last year after the allegations were aired by BBC Panorama, said outside parliament: "I am an ex-soldier and I believe that when I have got something wrong you've got to 'fess up and get on with it. No point in shilly-shallying and trying to avoid it. What has happened has happened. I am ashamed of it.

"Therefore I am going to do what I can to put it right for the constituency of Newark … to put it right for my family and for my wife who have been under such pressure for the last year. [I] make it quite clear that I argue with nothing with what the committee or may not have said because I still don't know officially what has been said. But with a great heaviness of heart – and I am hoping that the people of Newark in Nottinghamshire will be able to tolerate me in the future – I am going to resign my seat in God's county of Nottinghamshire in the town of Newark. I hope that my successor, who has been well and carefully chosen, will be the Conservative candidate."

Mercer was supported by the Tory MPs Bob Stewart, a former army colonel, and Bernard Jenkin. One senior Tory commended Mercer, saying: "When death is inevitable all you have left is style."

The byelection will be a challenge for Cameron and Labour, which came second in 2010, could mount a serious challenge. Labour held the seat for one parliament after capturing it from the Tories in 1997.

Councillor Stuart Wallace, chairman of the Newark Conservative Association, said: "The association wish to express our thanks for the work Patrick has done for Newark and for many of his constituents individually, over the last 13 years, both as a Conservative and as an independent MP.

"Following Patrick's earlier decision not to stand again, we selected a superb candidate, Robert Jenrick, who has already been very active locally. The association are united in support for Robert and will be campaigning to ensure that he will be elected as Newark's next MP. "

The recommendation of a six-month suspension by the standards committee is one of the most severe penalties that can be imposed on an MP. Mercer resigned the Tory whip last year "to save my party embarrassment" after he accepted £4,000 from undercover reporters posing as lobbyists. He failed to declare £2,000 of the money.

Journalists working for the BBC Panorama programme recorded Mercer agreeing to set up a parliamentary group to campaign for the return of Fiji to the Commonwealth. Panorama reported that Mercer has submitted five parliamentary questions in relation to the new group.