Supporters of British MP George Galloway say the government's decision to block him from entering Canada is a "clear attack on free speech."

Galloway, an anti-war advocate who has resided in the British House of Commons for the past 23 years, is currently on a speaking tour of North America, which includes dates in Canada.

Two weeks ago, allegations surfaced that he had financially supported Hamas, a group that Canada defines as a terrorist organization. On a preliminary basis, the Canada Border Services Agency decided to block Galloway from entering Canada.

Heritage Minister Jason Kenney then said he would not intervene in that decision.

At a rally on Parliament Hill Wednesday, Toronto Coalition to Stop the War co-ordinator James Clark called on Kenney to change his stance.

"We categorically reject any accusation of terrorism against Mr. Galloway and instead believe that Mr. Kenney's decision to intervene in this manner is a politically driven one to prevent the airing of views with which Mr. Kenney disagrees and which are critical of his government's foreign policy," Clark told reporters.

The organizers of Galloway's speaking tour have launched a civil liberties campaign at and have been lobbying the Conservatives to reverse the ban.

Meanwhile, a lawyer representing Galloway will ask a court Wednesday to review the decision by federal officials to block his entry into Canada.

A federal court in Ontario will hear the application, which will be filed by Toronto immigration lawyer Barbara Jackman.

Jackman will also file a motion for an injunction on the ban.

In an interview with CTV's Power Play Tuesday, Galloway said he is not and has never been a supporter of Hamas.

Galloway said he travelled to Gaza City earlier this month to deliver 100 ambulances and vehicles stuffed with medical supplies, which he valued at roughly 800,000 British pounds.

He said he gave the supplies to Hamas only because the group is the territory's government, but they were meant for the Palestinian people.

Galloway said he's going to fight the decision and make sure Canadians are allowed to hear him speak.

"One way or another, the thousands of people who have bought tickets to hear me, in four different places, will hear me," he said.

"The technology exists through which I can still get my message across. I suppose in a perverse way, Minister Kenney's decision has further increased the audience, one way or another."