The British government must follow through with its threat to call an election in Northern Ireland, Sinn Féin has insisted.

Former Sinn Féin finance minister Conor Murphy was commenting after Northern Ireland Secretary Chris Heaton-Harris failed to set a date for a new election on Friday, despite repeatedly indicating he would as a legislative deadline for calling a poll approached.

The 24-week deadline for forming a functioning power-sharing executive in Belfast following May's election ran out at midnight early on Friday.

A DUP boycott of the devolved institutions, in protest at Brexit's Northern Ireland Protocol, prevented an administration being formed in the wake of May's poll.

Once the deadline passed on Friday, the UK government assumed a legal responsibility to call a fresh election within 12 weeks.

Mr Heaton-Harris insisted on Friday he still intended to call an election but failed to set a date, prompting Northern Ireland's chief electoral officer, Virginia McVea, to apologise to election workers who are on standby to assist on the basis polling day will be 15 December.

The Secretary of State said he would say more about an election this week after holding talks with the local parties, which are scheduled to take place tomorrow.

He also indicated he would potentially take action to cut the pay of MLAs.

Downing Street said it is "not aware" of any plans for an update on an election in Northern Ireland during the talks with leaders over the coming days.

Asked if there will be an update from Mr Heaton-Harris with regard to the election, the prime minister's official spokesman said: "I'm not aware of any plans for that during those visits.

"The rules are the date needs to be announced as soon as reasonably practicable. But I don't have an update for you."

Pressed on whether an election still has to go ahead even if an agreement is made in the coming days, he said: "Our sole focus is on the obligations and legislations placed on the UK and restoring stable, accountable and locally elected devolved government in Northern Ireland."

Chris Heaton-Harris is also to meet Minister for Foreign Affairs Simon Coveney later in the week

Commenting on the developments, Mr Murphy told BBC Radio Ulster: "It's just, I think, symptomatic of a general degree of chaos that's going on within the Conservative Party over the last number of months.

"We've been collateral damage from that. And I suppose the irony is the DUP are holding out and preventing us from forming an Assembly and an Executive on the basis that they will have some influence over the Conservatives, and you can see very clearly with the chaos that's going on there, that that strategy isn't working and that the only people that are suffering as a consequence of that strategy are the people that we collectively represent.

"So, we're no clearer today than we were on Friday as to what the Secretary of State intends to do.

"We've been very clear that we want to see the Executive and the Assembly up and running. That deadline has now passed because the DUP prevented it again last Thursday, and so now the law requires us to move to an election and that's what we need to do.

"The DUP are holding out to get some certainty from a Government that isn't certain itself about what it's doing, and it's preventing the rest of us from getting on with the business of providing support to people here in the middle of a cost-of-living crisis."

The DUP's former economy minister Gordon Lyons suggested the British government had wrongly believed that its threat about calling an election would force his party to drop its block on power-sharing.

"I think that the feeling within the Northern Ireland Office was a threat of an election would change the DUP's mind - it's not going to," he told BBC Radio Ulster.

Mr Lyons said talk of an election was a "distraction" from the "real work" the government needed to do to resolve issues with the protocol.

The DUP says it will not return to power-sharing until decisive action is taken to remove economic barriers on trade between Great Britain and Northern Ireland.

The British government has vowed to secure changes to the protocol, either by a negotiated compromise with the EU or through proposed domestic legislation, the Northern Ireland Protocol Bill, which would empower ministers to scrap the arrangements without the approval of Brussels.

Mr Heaton-Harris is also to meet Minister for Foreign Affairs Simon Coveney later in the week.