OTTAWA -- A report published online by Maclean's magazine says NDP Leader Thomas Mulcair was in discussions in 2007 to join the Conservative party as a senior adviser on the environment to Prime Minister Stephen Harper.

Several sources told the magazine that the discussions were the first step in securing Mulcair to run as a Conservative candidate in 2008 but the negotiations allegedly broke down over money, with Mulcair seeking nearly double what Harper's office offered.

Dimitri Soudas, who was Harper's press secretary at the time, told Maclean's he was authorized to offer up to $180,000 a year but Mulcair wanted $300,000. Soudas says after he said he couldn't go higher than $180,000, he never heard from Mulcair again.

Mulcair says conversations about an advisory role with the government began in 2006, but talks broke down over the Conservatives' environmental policies and not over money.

He denies negotiating with Soudas and says he had no intention of running for the Conservatives.

Mulcair at the time had recently resigned as environment minister in Jean Charest's Quebec Liberal government. He joined the NDP in April 2007 and won a by-election in the Montreal riding of Outremont five months later.