LISBON, Portugal – Tony Blair once infamously told President Bush in a not-meant-to-be-heard moment that he was the perfect person to undertake a peace mission to the Middle East _ because he would not be expected to get results.

But when the former British prime minister debuts as Middle East envoy on Thursday, he won’t have the luxury of low expectations.

“The reality is there has to be a breakthrough, there has to be an agreement between Israel and the Palestinians, and Tony Blair is going into this at the worst possible time,” said Mike Gapes, a British lawmaker who heads Parliament’s Foreign Affairs Committee. He noted that the Palestinians have been split by Hamas’ violent takeover of Gaza, and Israel is hampered its prime minister’s low popularity.

Following a whistle-stop tour of European capitals this week, Blair was to confer with leaders of the international Quartet for peace in the Middle East in Portugal on Thursday, ahead of a possible trip to the region this month.

Out of office for just three weeks, supporters say Blair brings enthusiasm and optimism _ as well as gravitas _ to his new job. They point to his leading role ending the decades-old conflict in Northern Ireland, and say he could do the same for the Middle East.

Detractors _ including much of the Arab world _ say such talk is a pipe dream.

Blair, they say, has too much baggage from his decision to join the U.S.-led war in Iraq, and from his reluctance to push Israel to halt its deadly bombing of southern Lebanon during last year’s war against Hezbollah.

“If there is an award for the combined negative credibility of an institution plus an individual, the Quartet and Blair should be its first recipients,” Rami G. Khouri, a prominent Lebanese columnist, wrote recently in Beirut’s English-language Daily Star. “Appointing Tony Blair as special envoy for Arab-Israeli peace is something like appointing the Emperor Nero to be the chief fireman of Rome.”

Such skepticism does not run as high among Palestinians, at least those loyal to President Mahmoud Abbas.

Saeb Erekat, a top Abbas aide, welcomed Blair’s involvement, saying he has been “consistent” in his calls for a Palestinian state alongside Israel, and in his opposition to Israeli settlements in the West Bank.

The Israelis are excited about Blair’s debut. Government spokeswoman Miri Eisin said there is “no question” the former British leader’s stature and experience would help. She said if Blair is successful, it would be “a real step toward an independent Palestinian state.”

Blair’s first day on the job comes during a busy _ and largely positive _ week for Middle East peacemaking. On Monday, Bush announced plans for a major peace conference, and talks this week between Israeli Prime Minister Ehud Olmert and Abbas brought promises of a release of 250 Palestinian prisoners, and an agreement to free up much-needed funds for the Palestinians.

Paradoxically, Abbas’ stunning loss of the Gaza Strip to Hamas last month has served as the impetus for progress, with Israel and Washington seeking to bolster the Palestinian leader’s standing in the West Bank.

While Blair has been hailed as a historic figure by Washington, the Bush administration has also made clear he is not to overstep his mandate. Officially, Blair is restricted to working with the Palestinians to develop infrastructure and their economy, while Secretary of State Condoleezza Rice remains the lead peacemaker.

Rice will be in Portugal on Thursday to represent the United States at the Quartet meeting, which also includes leaders from the European Union, Russia and the United Nations.

Notably, it was a 2006 conversation with Bush over whether Rice or Blair should travel to the Middle East that perhaps defined the low point of Blair’s premiership.

As the president buttered a bread roll during a Group of Eight meeting in St. Petersburg, Russia, last July, Blair dutifully offered to go to the region.

When Bush replied that Rice would take on the task, Blair made one last pitch: “Obviously, if she goes out she’s got to succeed,” he told the president, “whereas I can go out and just talk.”

The conversation was meant to be private, but was caught by a microphone. Critics say it sealed Blair’s reputation as an American lackey, and he was lampooned endlessly.

Blair has kept a low profile since leaving office as new Prime Minister Gordon Brown won high marks for his calm stewardship of the investigation into a failed terror plot.

That hasn’t stopped British tabloids from running stories about the Blairs’ return to “civilian life.” Residents near the family’s new London home say the couple introduced themselves at a garden party not long after Blair left office.

And neighbor Alison Lloyd told the Daily Mail newspaper that Blair’s wife, Cherie, called on her at home. “I was doing the washing up and was still wearing my apron. I said, ‘as you can see I’ve dressed up for the occasion’ and Cherie roared with laughter,” Lloyd told the newspaper.

Garden parties will not likely be high on Blair’s agenda for long _ regardless of the odds against him, his new job does offer one thing: a chance for a quick return to the world stage.

Associated Press reporters David Stringer in London and Josef Federman in Jerusalem contributed to this report.

A service of the Associated Press(AP)