Top Liberal Democrat MP David Laws called a party activist "hysterical" as grassroots activists and the upper echelons of the party clashed at conference.
Schools minister Laws made the verbal slap-down of Naomi Smith of the Social Liberal Forum for her demand that Nick Clegg should be replaced as leader if the Lib Dems do badly at the 2014 local and European elections.
Smith, who is co-chair of the left-leaning thinktank, and Laws clashed as the party gathered for its annual conference in Glasgow.
Smith said that Clegg was tucked up in the pockets of David Cameron and chancellor George Osborne. She said the relationship was like something out of 1980s puppet satire, Spitting Image.
"We know he's against his party on [many] issues and all he seems to be for is propping up George Osborne's economic policy," she told the BBC.
Laws called the comments hysterical and accused "extremes" in the party of "throwing pebbles."
The fallout between the left and right wings of the Lib Dems comes as the leadership prepares for a potentially embarrassing conference debate about the economic policy of the coaltion government. Members could fail to endorse austerity policies in a motion vote.
Smith said of Clegg: "[It's] like something out of Spitting Image. If we had it today we'd probably have Nick Clegg in Cameron's hip pocket. Certainly, the polls haven't been very good for him within the party.
"We are facing a very real prospect next May of appalling European election results and local election results for the fourth year on the trot. If that's what we're facing, we need a change of direction - and soon."
Smith also accused Clegg and other members of the coalition government of being out of touch with party members.
"The way the leadership seem to have been briefing this is that they're fighting the left of the party on the economy, but I think that's a misrepresentation. I think he's fighting what's left of the party."
Laws said: "Naomi's analysis was somewhat hysterical and bears no resemblances to the discussion I'm having with large numbers of party members here at the conference. I don't think it represents the views of many of the party members at Glasgow.
"Let's be sensible and realistic and let's also not have members of the public sitting on the sidelines throwing pebbles, but actually championing the massive achievements in Liberal Democrats in this government
"Some of our members on the extremes can champion our achievements a little bit better than they are doing."