SDLP leader Colum Eastwood has urged DUP leader Jeffrey Donaldson not to "bow down" to threats of loyalist street protests if the unionist party returns to Stormont.

It comes after loyalist blogger Jamie Bryson sent a letter to three unionist party leaders over the weekend warning that any return to Stormont would see "a return to mass street protests".

Speaking at the opening of SDLP councillor Paul Doherty's new office in West Belfast on Tuesday, SDLP leader Colum Eastwood called on Mr Donaldson to be "very careful".

"I think Stormont can get up and running but it takes a bit of political courage from the DUP," he said. "Jeffrey Donaldson needs to be very careful and not be cowed by the leader of the Blue Bin Brigade.

"Jeffrey has been warned that loyalists will stage mass street protests if his party returns to Stormont without the Protocol being scrapped.

"Jamie Bryson has had his chance at street protests over the last number of years and with people supposedly extremely angry, it hasn't exactly developed. Where were these mass protests?"

A new system for moving goods from Britain to the North came into play at the weekend as part of the Windsor Framework. On Sunday, a new trusted trader scheme came into effect with a system of "green and red lanes" at ports here.

Mr Eastwood said such changes are not what people are worried about.

"The only place for Unionism and Nationalism now is to work together," he added. "People that I talk to don't care what a green lane is or a red lane is. They don't know what they are.

"What people do care about is that we have the highest waiting lists in all of these islands, their children can't get nursery school places. People are concerned about the cost of living, about benefits, trying to get a job and about looking after themselves and their families.

"Hopefully Jeffrey Donaldson will realise that soon and we can get on with things.

"During the last period of collapse, I said that if there is no power sharing Executive at Stormont, the only way to give true voice to the Good Friday Agreement is Joint Authority in the North."

Asked about the inevitability of a border poll by 2030 – which the SDLP leader called for last month – Mr Eastwood urged caution.

"I don't believe in inevitability. That is when you get complacent. There are a lot of people not convinced about it and a lot of people thinking about it that didn't before.

"I am absolutely sure the SDLP are the right party to convince people. Even on our worst electoral days, we are still the most transfer friendly party across the North.

"We want to play our part in bringing people together to deliver a new Ireland."