Federal Environment Minister John Baird has been called to appear before a House of Commons committee looking into whether he meddled in Ottawa's last municipal election.

Last week, the standing committee on government operations and estimates heard from several officials involved in Ottawa's failed attempt to build a north-south light-rail system.

In fall 2006, when Baird was Treasury Board president, he withheld $200 million in federal money for the project until after that November's mayoral election.

Mayoral candidate Larry O'Brien was opposed to the rail plan. He went on to defeat outgoing mayor Bob Chiarelli, who was in favour of the project.

Baird has been asked to appear before the committee later this month, after the March break.

The original motion also called on O'Brien and his former communications director, Mike Patton, to appear, but those names have been removed from the witness list.

When the committee announced in February it would investigate Baird's actions, the environment minister said he made the right decision when he acted as he did.

"If you want to avert a billion-dollar boondoggle, you have to make some difficult decisions," he told reporters.

He dismissed the investigation, adding that the federal ethics commissioner earlier declined to probe the incident because "there's no evidence of anything."