UUP and DUP in public row

The row outside the UUP HQ lasted for up to 10 minutes

The leaderships of Northern Ireland's two main unionist parties have been involved in a bitter street confrontation during election campaigning.

UUP leader David Trimble and DUP counterpart Ian Paisley were present at the incident in east Belfast on Tuesday.

It took place after the DUP unveiled a mobile billboard outside the UUP headquarters.

A short time later, Mr Trimble and other senior Ulster Unionists emerged from Cunningham House to confront the DUP delegation.

They became involved in a row with DUP deputy leader Peter Robinson, Strangford MP Iris Robinson and former MP William McCrea.

Mr Trimble again challenged Mr Paisley to a TV debate. Both sides engaged in a stand-off and attempted to shout each other down.

Peter Robinson said Mr Trimble was "yesterday's man", while the UUP leader accused the DUP of "hiding" its leader during the election campaign.

Mr Paisley had unveiled a billboard outside the UUP offices

The DUP members said Mr Trimble was unable to campaign in Portadown, in his own Upper Bann constituency.

"You can't even walk in your own constituency," said Iris Robinson.

However, the UUP leader said he had canvassed in the County Armagh town.

The DUP members began shouting: "Where is Jeffrey?" - in reference to rebel UUP MP Jeffrey Donaldson."

Mr Trimble replied: "Jeffrey agrees with our manifesto - he issued a statement to that effect today."

He accused Peter Robinson of shielding Mr Paisley.

However, Mr Paisley denied he was "hiding".

Both sides exchanged insults for up to 10 minutes before Mr Trimble was driven away.

The DUP members later left in the party's 'battle bus'.

At the weekend, the DUP dismissed a challenge for Mr Paisley to participate in a television debate with Mr Trimble.

Mr Trimble had accused Mr Paisley of "running away" from television studios during the Northern Ireland Assembly election campaign.

Mr Trimble said Mr Paisley needed to state his position on being in government with Sinn Fein.

'Genuine preference'

Meanwhile, SDLP leader Mark Durkan urged voters "not to give Ian Paisley his last hurrah".

"Give him his marching orders. Give your first preference to the SDLP," said Mr Durkan.

"Give your transfers to other pro-Agreement candidates to stop the anti-Agreement forces in their tracks.

We would like to see the unionist community coming back and saying we respect that decision taken through a peaceful and democratic process Mitchel McLaughlin Sinn Fein

"And if you are giving your first preferences to other parties, I am asking you to give your transfers to the SDLP. As the strongest and clearest pro-Agreement party, people know that a preference for us is a genuine preference for the Agreement."

Also on the campaign trail, Sinn Fein's Mitchel McLaughlin said the issue of united Ireland was "an issue for the people".

"We have said that we will take this status quo that we disagree with and we will work it and we will work with you (unionists) to ensure that we deliver better social and economic experiences and realities in future for the people who live here.

"We will respect the fact that a majority exists in the present circumstances to retain the link with Britain... but when a majority emerges for a united Ireland - which it will - we would like to see the unionist community coming back and saying we respect that decision taken through a peaceful and democratic process."