Two American peace activists who were denied entry into Canada because they had been arrested for taking part in anti-war events in the U.S. say they will try again to cross the border.

Ann Wright and Medea Benjamin said they plan to fly to Ottawa on Thursday, where they are to be greeted by several New Democratic MPs, including former NDP leader Alexa McDonough.

The activists and their supporters presented petitions Tuesday at Canadian consulates in several U.S. cities, demanding that Canada reverse what they say is a policy that keeps foes of the Iraq war from visiting.

The two women said they were informed during an earlier attempt to visit Canada in August for a summit of North American leaders that their names were in an FBI database designed to track fugitives, violent felons and terrorism suspects. The database listed them for convictions on misdemeanour charges of trespassing.

Benjamin, co-founder of the peace group Code Pink, and Wright, who resigned from her diplomatic post in 2003 in opposition to the U.S. invasion of Iraq, were told they would have to apply for "criminal rehabilitation" and pay $200 if they ever wanted to visit again.

The women walked into Canada at Niagara Falls on Oct. 3 to test whether they really would be denied entry and were turned back.

"The Bush administration has convinced the Canadian government to do its dirty work, to deny entry to people who are dissenting against Bush administration policies," said Wright, a retired Army colonel and diplomat.

Darren Brunk, a spokesman for McDonough, said she and five other MPs sent a letter to Prime Minister Stephen Harper on Friday advising him that they had invited the activists.

"We trust that you will ensure unimpeded entry into Canada, to enable Ms. Benjamin and Col. Wright to share their message of peace with members of Parliament and the broader community," they wrote.

Paul Copeland, an immigration lawyer in Toronto, said there are no criminal trespass provisions in Canada's Criminal Code that are equivalent to a trespass misdemeanour in the U.S.

"There's no basis to keep them out," he said.

Chris Williams, spokesman for the Canada Border Services Agency, would not comment on specific cases but said border guards consider the facts on a case-by-case basis to determine whether an applicant gains entry into Canada.

"Ultimately, with any travellers visiting, it's up to them to satisfy the border service officer when they attempt to cross the border," Williams told CBCNews.ca on Wednesday. "The standards for admission have not changed for a long time."

With files from the Associated Press