|Tony Blair, right, with Gordon Brown at London press conference|
No one predicts that Labor will retain such a big advantage, but most opinion polls point toward a Labor victory on May 5.
Political scientists will watch to see how many seats Labor loses, and what impact it will have on Mr. Blair's power base. There is a dedicated group of 30 to 40 Labor lawmakers who have voted against Blair initiatives, ranging from college tuition fees to anti-terrorism laws, and they could upset the government's agenda, if the Labor majority is sharply reduced.
A political scientist at the London School of Economics, Patrick Dunleavy, says he has been discussing the matter with fellow experts.
"Some people suggest that, if the Labor majority falls below about 40, life would not be very easy for Tony Blair," he said. "I know very respected parliamentary colleagues who think a Labor majority of less than 40 would be unworkable."
Voters tell pollsters that domestic issues, such as health care, taxes and crime are their main concerns. But some Blair opponents also want to make an issue of the Iraq war, especially the controversy over government documents based on false intelligence that claimed Iraq had weapons of mass destruction.
A Conservative Party spokesman, George Osborne, says that, while his party also supported the war, it believes the way Mr. Blair handled it has undermined his credibility.
"The trust people have in him has collapsed," he said. "So, the Iraq war has had an impact on this election, but I think the impact is primarily on the trust people have in the prime minister."
The Labor Party wants to keep the focus of the campaign on the British economy, the strongest among major European countries.
Finance Minister Gordon Brown says the party's manifesto emphasizes the need for steady stewardship.
"Stability is the foundation of our economic success," he said. "We will never take any risks with the hard won economic stability of this country. Our commitment to investment in our priorities is based on detailed published plans and meeting all our fiscal rules."
Mr. Brown has assumed a major role in the Labor Party campaign, a tacit concession to the controversy surrounding Mr. Blair. Prime Minister Blair has already announced that, if Labor is re-elected, he will step down sometime during the next parliament, and Mr. Brown is widely seen as his most likely successor.