Image copyright BBC NI press office/William Cherry Image caption The panellists, from left, were Mike Nesbitt (UUP); Naomi Long (Alliance); Mark Durkan (SDLP); Martin McGuinness (Sinn Féin) and Nigel Dodds (DUP)

Northern Ireland's five biggest parties have clashed over welfare reform and gay marriage in the final TV election debate before voters go to the polls.

The NI leaders' debate took place at the BBC but only one of the parties was represented by its leader.

UUP leader Mike Nesbitt accused Sinn Féin of costing Northern Ireland "£2m a week by reneging on your commitments" in the recent Stormont House Agreement.

Sinn Féin's Martin McGuinness said the UUP had "signed up" for welfare cuts.

"You were a member of a party that signed up, through UCUNF [Ulster Conservatives and Unionists, New Force]... which resulted in the withdrawal of £1.5bn from our budget," Mr McGuinness said.

'Regret'

Sinn Féin withdrew its support for the Stormont House Agreement in March, three months after the five-party deal had been struck on a wide range of issues, including welfare reform.

On the issue of same-sex marriage, the UUP leader and the DUP's Nigel Dodds said they believed marriage should be between a man and woman.

Mr McGuiness, the SDLP's Mark Durkan, and Naomi Long from Alliance supported equal marriage rights.

Image caption The parties clashed on the issues of welfare reform and same-sex marriage

Both Mr Durkan and Mrs Long expressed regret that several MLAs from their parties were either absent or had abstained from a recent Northern Ireland Assembly vote on sex-same marriage.

Mr Durkan said the SDLP was the first party to propose the decriminalisation of homosexuality, the equalisation of the age of consent and civil partnerships.

He said the SDLP's "party policy is clear" on the issue of same-sex marriage and called for legislation to be passed.

'Hypocrite'

Mrs Long said: "I share the disappointment that not all of my colleagues have voted in favour of this legislation."

She said that her party was "working our colleagues to address their concerns around the issue" and added that "no-one has equality when it is denied to anyone".

Image copyright BBC NI Press Office Image caption The debate was chaired by BBC presenter Noel Thompson

The recent controversy involving Health Minister Jim Wells, who resigned after linking same-sex parents to child abuse, was raised in the debate.

Mr Dodds said Mr McGuinness was a "hypocrite" for demanding an apology from Mr Wells but not offering an apology for IRA murders during the Troubles.

The DUP deputy leader said: "The fact is that we do not believe in the redefinition of marriage, but that does not make you anti-gay."

'Pulled out'

Mr Nesbitt said he had a "zero tolerance for homophobia" but had voted against same-sex marriage because he "was brought up in a church that believes that marriage is between a man and a woman".

Mr McGuinness repeated his party's call for a referendum on same-sex marriage, to allow the people of Northern Ireland to decide.

The parties also clashed over how to deal with the legacy of the Troubles and Sinn Féin's policy of refusing to take their seats at Westminster.

All five party leaders were invited to the debate but only the UUP leader accepted, with the other four sending senior party members.

BBC presenter Noel Thompson said: "Until this morning, we had been expecting the SDLP leader but Alasdair McDonnell pulled out, with the party saying that was 'in line with the DUP and Alliance'."

The debate was broadcast on BBC One Northern Ireland but you can watch it again here and you can watch the NI Leaders' Debate: Reaction here.