OTTAWA - Liberal Leader Michael Ignatieff and NDP chief Jack Layton are scoffing at a media report suggesting their parties are discussing a merger.

Ignatieff said the idea is "ridiculous."

Layton called it "fiction."

The two leaders reacted Wednesday to a CBC report in which Liberal strategist Warren Kinsella said senior Grits were involved in "serious" negotiations to unite the centre-left under a new Liberal-Democratic party banner.

"No one has any authorization to even discuss this matter," Ignatieff said following a Liberal caucus meeting.

"It's ridiculous."

Emerging from his own party's caucus meeting, Layton was equally categoric.

"It's not a fusion, it's a fiction," he said.

Talk of a merger, coalition or some sort of electoral co-operation between the two parties has been bubbling for weeks, largely fuelled by Liberal concern about tepid poll numbers and encouraged by the example of the Conservative-Liberal Democrat coalition which took power last month in Britain.

Much of the talk is laced with an undercurrent of dissatisfaction with Ignatieff's leadership.

But the merger report seemed to have a unifying effect Wednesday.

Ignatieff was flanked by two erstwhile leadership rivals — Bob Rae and Dominic LeBlanc — as he insisted his leadership is "solid."

"Solid, solid, solid," put in Rae.

Kinsella has been promoting the idea of a merger for some time on his website.

He was brought on board the Ignatieff team last fall to run the Liberal war room in an election the leader was promising to force. When the election threat fizzled, Ignatieff replaced his inner circle, precipitating a falling out with Kinsella.

Ignatieff now says: "I have no relationship with Warren Kinsella."

NDP national director Brad Lavigne pointed out that he regularly appears on television panels with Kinsella. He said Kinsella has not once broached the idea of a merger with him.