Sinn Fein has declined to re-nominate a Stormont deputy first minister in a move set to collapse the powersharing executive in Belfast and trigger a snap election.

Barring a highly unlikely u-turn by the republican party, the institutions will now fall at 5pm on Monday and Northern Ireland Secretary James Brokenshire will be legally obliged to call the election.

Sinn Fein declined to replace Mr McGuinness at the start of Assembly business at Parliament Buildings on Monday.

The Sinn Fein veteran quit over the Democratic Unionists’ handling of a botched green energy scheme.

Sinn Fein MLA Michelle O’Neill told the Assembly: “The DUP have treated these institutions and sections of the community with contempt and arrogance.”

She added: “Today Sinn Fein will not re-nominate for the position of deputy first minister.”

Ms O’Neill said Sinn Fein would only return to government if there was “real and meaningful change”.

Earlier, DUP leader Arlene Foster had agreed to be renominated as first minister.

Speaker Robin Newton said both ministers needed to be in post for their office to function.

“Those requirements have not been met and the office of the first minister and deputy first minister must remain vacant,” he said.