Tory MPs who used a vote on adoption to air their disquiet about Iain Duncan Smith's leadership risk losing the support of the party's grassroots members, it was claimed.

Chairmen of some Conservative constituencies have warned that the party's future could be in jeopardy if MPs do not pull together and stop their very public infighting.

People that are working against Mr Duncan Smith ought to think very carefully about the future of the party

Lesley Steeds East Surrey Conservatives

They were reacting to Mr Duncan Smith's warning to disaffected MPs that they must unite behind his leadership if the party is to be taken seriously.

His message followed a rebellion by Tory MPs over the right of unmarried and gay couples to adopt children.

But Rod Reed, an outspoken critic of Mr Duncan Smith and chairman of Beckenham Conservative Association in Kent, said it was "pretty unlikely" that ordinary members would come to his aid.

'Serious trouble'

That view was countered by Lesley Steeds, chairwoman of the East Surrey Conservatives, who described the Tory leader's "unite or die" speech as "excellent".

Mrs Steeds' local MP Peter Ainsworth failed to vote on the adoption issue despite a three-line party whip, although she said she did not know why.

John Bercow 'is not plotting' against Iain Duncan Smith

But, she stressed: "I think the people that are working against Mr Duncan Smith ought to think very carefully about the future of the party.

"They are unsettling the grassroots and once they lose the base of the grassroots, they will be in serious trouble.

"Mr Duncan Smith has got my support. He sent out the right message.

"I think he must be wondering why he took the job of leader on."

'Stop fighting'

Buckingham MP John Bercow stepped down as shadow work and pensions minister because he could not vote against government plans to allow unmarried couples to adopt.

But his constituency association chairman Sir Beville Stanier insisted that the MP was "not plotting" against the party and said he supported the Tory leader's call for party unity.

"I think it was a very sensible speech by Mr Duncan Smith," said Sir Beville.

"People who are detracting from his leadership and what he is doing are not helping.

Tory MP Julie Kirkbride voted against her party over adoption

"All of this gives Labour such a huge advantage - it's time it stopped.

"I am 100% supportive of John Bercow. John's not plotting against the party. He made a decision on his conscience, that he could not vote against the adoption proposal."

Daniel Moylan, deputy leader of Kensington and Chelsea Council, said local MP Michael Portillo, a former leadership contender, had "shown no sign at all of any disloyalty" to Mr Duncan Smith.

He supported the Tory leader's message, adding: "I think the party does have to stick together and that's what we'll do."

'Malcontents'

Bromsgrove MP Julie Kirkbride was another of the eight Tories to defy a three-line party whip on adoption.

Peter Jarrett, chairman of Bromsgrove Conservative Association, said the party needed to stop the "internal fighting" and stressed that Mr Duncan Smith had been "wrong" to whip his MPs on adoption.

"We need to get away from a situation where we are fighting internally," he told BBC News Online.

"Yes, we must unite or die. We must all be there to support policies that the Conservative party are putting forward.

"At the moment it all seems to be down to personalities and we must get away from that.

"The Conservative party has lived with having people in the party who are malcontents, going back to 1992 - there will always be people who are rebels.

"Really, we are looking for a lead from the parliamentary party on what to do next."

Morale is at rock bottom

Rod Reed Beckenham Conservative Association

Mr Jarrett said Ms Kirkbride had acted on her "conscience" over the adoption vote.

"As far as I am concerned, this is not a political issue. The Labour party took the whips off and it was wrong to put a three-line whip on us. Totally wrong."

But Rod Reed argued that "morale is at rock bottom and a lot of people are saying quietly they are dissatisfied".

His Beckenham MP Jacqui Lait voted on the Tory line over adoption.

"The polls show more Conservatives are dissatisfied than satisfied," he said. "We are not talking about Conservative Association officers but Conservative supporters.

"If they are dissatisfied, what about the floating voters? They are the people we have to persuade."