Developments in the Northern Ireland political process could move very quickly if the government was prepared to make changes to policing and demilitarisation, according to Sinn Fein.

The party's Martin McGuinness said Tony Blair's speech last year about acts of completion must be lived up to.

He said he had yet to hear anything suggesting the prime minister was ready to move on issues such as policing.

The province's devolved institutions were suspended on 14 October 2002 following a row over allegations of IRA activity, including alleged spying within the Northern Ireland Office.

Martin McGuiness: Detailed meetings

Speaking in Belfast on Wednesday, Mr McGuinness said any deal on "acts of completion" hinged on Thursday's meeting between Tony Blair and Irish counterpart Bertie Ahern.

He warned against any attempt by the government to try and roll back on promises made in the Good Friday Agreement.

This would result in no progress before elections, he said.

'Deadline for progress'

The Mid-Ulster MP said there had been detailed meetings with the two governments, but cautioned against speculating about agreements already made ahead of Thursday's talks.

"I haven't heard or seen anything from the government which would indicate the British prime minister is up for acts of completion on policing, demilitarisation, human rights and equality," he said.

"Maybe in the aftermath of tomorrow's meeting will we hear a different tune being sung. If that's the case, then I think all of us will need to rise to the challenge."

He said St Patrick's Day (17 March) was regarded as a deadline for progress.

Sinn Fein said Thursday's meeting between the Irish and British prime ministers was the most crucial one the peace process has seen in 20 years.

Mr McGuinness said the next six to eight weeks of talks were the most critical in the last 100 years of Ireland's history.

Gerry Adams: Met Irish prime minister in Dublin

He and Sinn Fein President Gerry Adams met Mr Ahern in Dublin on Tuesday.

It was one of a series the taoiseach is holding this week in an attempt to revive the power-sharing assembly at Stormont.

An Irish Government spokesperson said the meetings would focus on areas "central to restoring trust and confidence among the parties in Northern Ireland".