LONDON (Reuters) - Sinn Fein, the political wing of the IRA, opened talks with British Prime Minister Tony Blair on Thursday amid hopes it would soon return to the Northern Ireland peace process. Sinn Fein was expelled from multi-party peace talks for 18 days after London and Dublin accused the Irish Republican Army of two murders. The expulsion order expired on Monday but Sinn Fein

said it wanted to meet Blair before deciding whether to go back to the talks. "We have been excluded at the whim of the securicrats and we won't collude in our own exclusion,"

Caoimhghin O Caolain, Sinn Fein's only MP in the Dublin parliament, told reporters at the start of the talks. "We have a chance now to tell the prime minister of our concerns at the double standards in the peace process," he said. Sinn Fein seeks an end to British rule in Northern Ireland and the creation of a united Ireland. Its leader Gerry Adams declined to comment as he entered Blair's official Downing Street residence. Blair wants a peace agreement in place by May so that people on both sides of the Irish border can be canvassed in referendums. Blair is convinced the prospects for peace are now better than they

have ever been -- even though 15 people have been killed since Christmas by rival guerrillas out to torpedo the talks. Sinn Fein's involvement in the peace process is crucial if Britain and Ireland are to win a settlement that could be endorsed by both Catholics and Protestants, alienated by a quarter century of sectarian strife.