Balance of power shifts to Paisley after defection of Donaldson from the UUP

The Rev Ian Paisley's Democratic Unionist Party took centre-stage in Northern Ireland politics yesterday when the rebel Ulster Unionist MP Jeffrey Donaldson joined its ranks. His defection from the UUP, with two other Assembly members, leaves David Trimble leading a weakened party well behind the Paisleyites.

The changed balance of power in Protestant politics gives other peace-process participants little scope for any deal excluding the DUP. In effect, Mr Paisley holds a veto over immediate prospects for a new political deal, and he is adamant that Sinn Fein "terrorists" are not to be contemplated in government.

Mr Donaldson has apparently been promised he will join the DUP negotiating team. He left the UUP last year, claiming he had suffered "vindictiveness and naked hatred". He said yesterday: "Mr Trimble and his colleagues had orchestrated a move to have me expelled from the party.

"I am proud to be part of a team capable of providing leadership to the Unionist community, not like the leadership of the party I left. Not like a leadership which has no bottom line, a leadership which does not know how to lead the Unionist community."

Mr Paisley, who announced a recruitment drive in the hope of further defections, described the move as "a historic day for Unionism". He added: "It is a good day because it means the Unionist people in Northern Ireland are going forward. They are not going back, certainly not going back to a table to get armed terrorists back into the government of Northern Ireland."

A review of the workings of the Good Friday Agreement will focus on exploring whether the DUP is interested in negotiating new arrangements in which republicans and nationalists would be included.

If it proves immovable there will be pressure for a new Assembly system in which the party might be outflanked. Although it is now the primary voice within Unionism, the Assembly has a clear majority in favour of the Agreement.

In last November's Assembly elections, the DUP overtook the UUP for the first time, and yesterday's development gives the Paisleyites a lead of 33 seats to 24. The loss of the three seats means Mr Trimble's party now has the same number of Assembly seats as Sinn Fein.