OTTAWA — Senior officials in Washington and Ottawa are working on a visit that could take Paul Martin to the White House a few days before a possible election call, The Canadian Press has learned.

That proximity to a potential election is prompting the prime minister to cautiously weigh U.S. President George W. Bush's invitation before accepting, sources say.

Negotiations leading to the visit have involved the highest levels of the government, including Martin himself last week.

The prime minister's chief of staff, Tim Murphy, and his American counterpart, Andrew Card, as well as Condoleezza Rice, national security adviser to Bush, and Jonathon Fried, the prime minister's senior foreign affairs adviser, have discussed a meeting in late March or on April 1 - the latter date just three days before Martin has the option of sending Canadians to the polls.

Martin's senior political staff are divided over whether he should make the trip so close to a possible election call.

Some have cautioned the prime minister that Bush's unpopularity with Canadian voters makes a visit to the White House a political risk.

Others are suggesting that there would be political points to score on the eve of an election, if Martin were to come out of the meeting with a tangible achievement beyond Bush's approval of the new impetus the prime minister has placed on Canada-U.S. relations.

Martin was able to emerge from his first meeting with Bush in January with what diplomats called two "deliverables." The U.S. president reversed himself and allowed Canada to bid on Iraqi reconstruction contracts, and he promised not to deport Canadians to third countries without prior consultation with Ottawa.

Those were concessions Bush made in Mexico, during a side meeting arranged at the Summit of the Americas, to a new prime minister who has made Canada-U.S. relations a priority.

The U.S. president was also anxious to turn the page after a tempestuous relationship with former prime minister Jean Chretien, and his officials suggested a more substantial meeting before he got too deep into the U.S. election calendar.

But the initial encounter set a fairly high standard for meetings between Bush and Martin. The prime minister's advisers are looking to meet that standard again with a concrete achievement before signing off on a White House meeting.

That achievement may be Bush's backing to open the U.S. border to live cattle exported from Canada.

The U.S. Department of Agriculture announced last week it would hear comment on whether Canadian cattle should be allowed back into the United States. An appeal in favour of reopening the border by the U.S. president during a meeting on April 1 - a few days before the 30-day comment period ends - would send a powerful signal to Congress and elements of the president's own administration that want to keep Canadian beef out of the lucrative U.S. market.

"Lifting the ban, particularly if it's lifted for all live cattle, would be a huge victory," said one government official working on the visit.

It could also serve as a powerful tool for the prime minister in the middle of an election campaign. Before the federal sponsorship scandal, Martin was hoping to make a significant breakthrough in Western Canada. Marshalling presidential muscle to help alleviate farmers' misery just before a campaign would undoubtedly help Liberal fortunes in cattle country.

Statistics Canada recently released figures showing that revenue from all livestock fell more than 11 per cent in 2003, the biggest decline in more than a decade. Cattle exports were hit the hardest, falling more than 66 per cent last year because of U.S. restrictions on Canadian beef imposed after mad-cow disease surfaced in Alberta.

But while a Bush call for reopening the border would be helpful, it might not be enough to get the deed done. The U.S. Department of Agriculture has the final say on cattle imports from Canada.

USDA officials are overseen by the U.S. Congress. Senators from U.S. border states, led by North Dakota Democrat Byron Dorgan, have made it clear they will fight any move to allow Canadian beef back into the United States unless it's clearly marked as having come from Canada.

That would make it far less palatable to American consumers who have been bombarded with news stories about the single Alberta-bred cow that was afflicted by the fatal brain-wasting disease - known formally as bovine spongiform encephalopathy, or BSE - and exported to a farm in the state of Washington.