Two high-profile politicians are poised for a battle over the chance to become the Green Party's first MP.

MEP Caroline Lucas has decided to take on Brighton's Green convener, Keith Taylor, in an attempt to be elected candidate for Pavilion at the next general election.

Promising European and council election results led think tank Forecast UK to predict it was increasingly likely the Greens would take the seat.

Analysis of May's local election results revealed the Greens received the highest number of votes in the constituency, just ahead of the Conservatives.

The Greens have made steady progress in Brighton Pavilion since 1997 and in the 2005 general election their second-time candidate Councillor Taylor recorded a 22 per cent increase in the party's vote.

But Dr Lucas, who is an MEP for the South East, has revealed in a confidential letter to party members that she wants to represent the party in Pavilion. One member, who asked to remain anonymous, said he was astonished by the in-fighting and bickering.

Dr Lucas, who was principal speaker of the national party alongside Coun Taylor until recently, revealed she would only take up the seat if she beat him by a margin of ten per cent to avoid internal division.

She refers to a fall-out in run-up to the local elections which saw the three initial Green candidates for Preston Park dumped at the last minute.

She wrote: "The reality is that, over the past few months, I have been encouraged to consider standing for selection in Brighton Pavilion.

"A number of local party members have asked me to do so, along with others whose views I value and respect. I have therefore spent some weeks agonising over what has honestly been the most difficult decision of my life.

"Not only are there personal and family commitments to consider but also, of course, my loyalty and commitment to Keith Taylor, who is a person and a politician for whom I have great admiration and respect. I also know how much contesting this seat means to him."

Dr Lucas has said if the general election was held at the same time as the European vote, in 2009, she would stand down as Pavilion candidate to concentrate on the Euro seat.

Coun Taylor said: "By the time of the general election I will have worked for ten years for the welfare of the local community.

"All the people know me here in Brighton and Hove and they know they can trust me.

"In the council elections in 2003 we doubled the number of councillors and in 2007 we doubled again.

"I have played a central part in these successes and in Pavilion I have secured a record for the Green vote."

Both candidates have said they will back the other if they fail to win.

Dr Lucas said yesterday she would not discuss her bid until nominations closed on Friday, adding: "Unlike the Labour Party, we don't believe it's democratic either to impose candidates from the centre or to brief journalists divisively while internal democratic procedures are under way."

The prospective parliamentary candidate will be announced on July 10.