Britain's Northern Ireland secretary Chris Heaton-Harris has urged the DUP to reform powersharing at Stormont as an election deadline looms.
The Conservative MP said politicians in Northern Ireland have choices they can make to stop an election being called.
But he reiterated that there is a legal obligation on the UK government to call an election if the Assembly is not formed by Friday.
His Conservative colleague, Britain's Northern Ireland minister Steve Baker said there will not be devolved government at Stormont until the “legitimate interest” of the Unionists to end the jurisdiction of EU law in Northern Ireland takes place.
It comes as Taoiseach Micheal Martin called on the DUP to “honour” the mandate of the people of Northern Ireland by contributing to the restoration of the Stormont institutions.
On Saturday, Mr Martin said it does not appear that devolved government at Stormont will be restored by Friday’s deadline.
Mr Heaton-Harris told Sky’s Sophy Ridge On Sunday that if six months passes without powersharing being restored after an election then another election has to be called.
“It’s actually a legal requirement to call it then at one minute past midnight on the 28th of October,” he said.
He added: “The Democratic Unionist Party have got an opportunity to come back in and it’s really important actually, I think, that they do because there’re so many domestic issues in Northern Ireland that would be helped by their re-entry into the executive.
“And they’ve got some really talented politicians themselves who can help solve those issues out.
“So there is a choice that people can make to stop their being an election.
“But it’s got to be made by elected representatives in Northern Ireland going back in to that assembly.
“Without that, the Secretary of State for Northern Ireland would have to call an election this week.”
Refusal
There is less than a week to form a Stormont executive before Mr Heaton-Harris will be obliged by law to call a fresh assembly election.
The DUP is refusing to nominate ministers to form a new executive until the Westminster Government takes decisive action on the Northern Ireland Protocol.
The party argued that the post-Brexit arrangements hamper trade and place sea border between Britain and Northern Ireland.
Mr Baker told Sky News that devolved Government in Stormont will not happen until the “legitimate interest” of Unionists to end the jurisdiction of EU law in Northern Ireland takes place.
He added the UK government’s current policy on the Northern Ireland Protocol “must be continued” no matter who becomes the next prime minister.
The Conservative MP has come out in support of Rishi Sunak in the Tory leadership race.
“The only policy that can be successfully carried through on Northern Ireland is the one that we have,” he said.
“And everyone should understand that because if say Rishi (Sunak) or Penny (Mordaunt) didn’t carry through that policy, the Eurosceptics would implode the government.”
He added that his Conservative colleagues will “not tolerate any diversion, any equivocation on this point”.
Mr Baker said nobody should be in any doubt that Mr Sunak would “follow through on the current policy”.
“The EU, and I hope they’ll hear me, the EU should understand there’s not going to be a change of policy,” he added.
Mr Baker also said he had taken “big hits” when he apologised for his previous stance on Brexit in a bid to “change the negotiating dynamic and the friendship between us and Ireland”.
“It’s working,” he said. “That’s great. But I didn’t just speak with humility.
“I also spoke with resolve everyone needs to understand that the legitimate interest of Unionists is to end the jurisdiction of EU law in Northern Ireland.
“Now that’s the hardest problem we need to solve.
“But we will not have devolved government in Northern Ireland until it’s done.
“That means we won’t be celebrating the 25th anniversary of the Good Friday Agreement.
“This is big stuff and everyone involved needs to understand we can offer both friendship, humility, we can make apologies where they’re needed.
“But in the end, we’ve got to end the jurisdiction of EU law in Northern Ireland.”