DUP leader Ian Paisley and Sinn Fein's Martin McGuinness are to take their pledge of office as devolution returns to Northern Ireland.

British and Irish Prime Ministers Tony Blair and Bertie Ahern will travel to Stormont to witness the ceremony later.

Direct rule over NI by London ministers officially ended at midnight, almost five years since it was brought back.

Ministers from the four main parties will take their pledge of office, which includes support for the police.

The return of devolved government follows an historic meeting in March between DUP leader Ian Paisley and Sinn Fein president Gerry Adams, where they agreed to share power.

Northern Ireland Secretary Peter Hain said he was confident the parties would make a go of it.

"It's going to stick, I believe, because the DUP and Sinn Fein -- Gerry Adams and Martin McGuinness on the one hand, Ian Paisley and Peter Robinson on the other -- these are the two most polarised forces in Northern Ireland's politics, they have done the deal," he said.

Ian Paisley Jnr of the DUP, who will be a junior minister in the government, said he was hopeful of success.

"We'd be foolhardy to be going into something if we didn't believe that it was going to be successful. We're planning for success, we're not planning for failure," he told the Today programme.

In October 2002, allegations of intelligence gathering within Stormont led to the suspension of power-sharing institutions. A subsequent court case collapsed.

Among the VIP guests on Tuesday will be US senator Ted Kennedy.

The DUP leader's wife Baroness Paisley and the Sinn Fein chief negotiator's mother Peggy McGuinness are also expected to attend.

A new speaker, the DUP's William Hay, is to be elected Assembly speaker along with three new deputies from the other main parties.

It is expected proceedings will be suspended for 30 minutes as a mark of respect to DUP MLA George Dawson who died on Monday evening.

The first meeting of the new power-sharing executive is scheduled for later this week.

PHOTO CAPTION

Martin McGuinness, a leading member of Sinn Fein (L), and leader of the Democratic Unionist Party (DUP) Ian Paisley, sit next to each other as they meet for talks with Chancellor Gordon Brown in Edinburgh on May 3, 2007. (Reuters)