Northern Ireland's political leadership was given a fresh mandate yesterday, but it remained unclear if it was a green light for former foes to form a ruling alliance, or for continued stalemate.

As vote-counting in the Stormont Assembly elections was concluded, the Rev Ian Paisley was given a second chance to lead a power-sharing executive, having refused to take up that option after his 2003 victory.

His Democratic Unionist Party (DUP) strengthened its grip on Unionist votes, while the once-dominant Ulster Unionists lost ground to the cross-community Alliance Party.

The rules of Stormont politics, agreed in the Good Friday Agreement, require Dr Paisley to work with Sinn Fein's Martin McGuinness as his deputy, after his party similarly gained ground against its rivals for Nationalist and Republican votes - and did so with highly effective voter management through the proportional voting system.

The DUP won 36 of the Assembly's 108 seats, up on the 2003 result by six, while Sinn Fein took 28, up by four. The Ulster Unionist Party, led by Sir Reg Empey, won 18 seats, down by nine, having previously had leadership at Stormont under David Trimble. The nationalist SDLP shared power until October 2002, but was yesterday down two seats to 16.

The cross-community Alliance Party were up one to seven seats, including the first Chinese-born member, Anna Lo. Progressive Unionists retained one seat, previously held by the late David Ervine, Greens broke through with a North Down seat, and UK Unionist Bob McCartney lost his seat.

With the results still coming in, Dr Paisley, who has made a long, successful career out of intransigence, was coming under pressure to take over the reins of a devolved administration, most notably from London and Dublin government leaders, who were together at a European summit in Brussels.

Prime Minister Tony Blair said the message from the Northern Ireland electorate was about water charges, health, education and the economy, "the real basic bread and butter issues of democratic politics. That is what is fascinating, very heartening and extraordinary about what has happened in Northern Ireland."

He went on: "Now is the right moment to reflect on those elections, the views of the people that were expressed in those elections and then get down to the business of running devolved government in Northern Ireland in an effective and satisfactory way for the people of Northern Ireland."

Dublin and London have imposed a deadline of March 26 for the two sides to remove remaining obstacles to a deal. Northern Ireland Secretary Peter Hain met Dr Paisley and the Sinn Fein leadership yesterday, but the DUP yesterday repeated its warning that any decision on power-sharing will not be dictated by deadlines, as it is "a condition-led, not a calendar-led party".

Deputy leader Peter Robinson reiterated those conditions; Sinn Fein must show total commitment to the role of the Police Service of Northern Ireland, and there must be a substantial economic package to help revitalise the economy, he said.

The DUP leadership knows its refusal to be rushed puts pressure back onto Downing Street, both because Mr Blair wants to get the devolved administration operating before he leaves office later this year, and because the demand for more money is aimed at Gordon Brown.

The British government's tactics, over recent months, have been to build public demand for a devolved administration by making sure that direct rule by Mr Hain has courted controversy and unpopularity - imposing local government reform and unpopular water charges.

Unlike the four-and-a-half years since the Assembly was suspended, its members will have their minds focused by a lack of salaries or support staff unless they get back to work.

Bertie Ahern, the Irish Taoiseach, added to the pressure for a deal, saying he looked forward to working with a devolved administration. "We will work in a determined way on north-south issues that are of relevance to us and we will continue to work on east-west issues with the Prime Minister."

If a devolved government is formed on March 26, Dr Paisley is his party's likely choice as First Minister, with Mr McGuinness as Deputy First Minister. On the basis of the results, the DUP could expect four ministries and Sinn Fein three, while Ulster Unionists and the nationalist SDLP will share the remaining three.