Northern Ireland's political parties have stepped up campaigning ahead of the assembly elections.

Ulster's politicians are set to spend the weekend on the campaign trail ahead of the November 26 vote.

The war of words has been stepped up with the SDLP and Ulster Unionists challenging DUP leader the Rev Ian Paisley to a TV debate.

Paisley claims his party is set to top the poll but has shied away from a face-to-face confrontation.

"Dr Paisley is running around the countryside avoiding studios, avoiding debate, avoiding participating with others," said UUP leader David Trimble.

"I have participated in debates. I have been doing with monkeys while the organ grinder is elsewhere. Now I want to have a proper debate at leadership level. So I challenge Dr Paisley - come and debate."

Paisley dismissed as "a complete lie" the suggestion he was dodging the debate.

The week has also seen the main political parties launch their manifestos.

Despite attempts to focus on issues such as education and a national sports stadium, the coverage has been dominated by issues related to the peace process.

Ulster Unionists warned that arms decommissioning must be settled before devolved government can be restored in Northern Ireland.

"We want to see the assembly restored but only when republicans have dealt conclusively with the issues of decommissioning," said Trimble.

The SDLP led its policy pledges with a controversial call for a referendum on a united Ireland.

The party said it would push for the poll during the lifetime of the next devolved assembly.

"As a positively nationalist party, we make clear our commitment to achieving a united Ireland in which the key features, rights and protections of the agreement will endure," said party leader Mark Durkan.

The Alliance Party called for the abolition of the quota system for Northern Ireland's police service.

The party said the 50:50 recruitment quota for Catholic and Protestant recruits, recommended by the Patten Commission, should be replaced.

Instead the cross-community party said it wanted to see a fairer system of affirmative action.

"Alliance has opposed the use of 50:50 quotas since the day the Patten Recommendations were published," said a party spokesman.

"The creation of a representative police service is something that is central to the new beginning of policing.

"However, Alliance has never believed that rigid quotas are the way to achieve it. Quotas are divisive as the place labels onto officers, discriminatory as they detract from the merit principle, and illegal."

It is thought that unionists will spend the next 12 days involved in a war of words - with the SDLP seeking to outflank Sinn Fein.

Both Durkan and Trimble hope to be able to do enough to see off the threat from their more hardline opponents in a bid to salvage the devolution process in the days following the assembly elections.