That's the end of our reaction and analysis on what's been a busy afternoon, following the decision by Martin McGuinness to resign as deputy first minister.

You can keep up to date with any further reaction and developments this evening and tomorrow on BBC News NI.

What happens now that the deputy first minister has resigned from the Northern Ireland Executive?

Martin McGuinness is stepping down after ten years in the post. He became one of Sinn Féin's two ministers in the first power-sharing deal that followed the Good Friday Agreement.

Image source, PA

Read Martin McGuinness' resignation letter in full here, external

Irish Foreign Minister Charlie Flanagan says he regrets the circumstances which had led to the resignation of Martin McGuinness.

"The substance of the RHI controversy is very much a matter for the devolved executive and assembly," he said. 

"However, the government is very mindful of the need to protect the integrity of the principles and institutions of the Good Friday Agreement."   

SDLP leader Colum Eastwood has responded to Mr McGuinness' resignation and said the "public understand that there is one reason for this potential election - Arlene Foster’s arrogance". 

Image source, Pacemaker

"The SDLP is ready to fight an election. Last May the executive offered a fresh start and have now failed - we will offer the public the chance of change,” he said 

“The public also knows that those behind ‘cash for ash’ scandal can now enjoy a two month break from any effective public inquiry or police investigation.”

Radio 4 PM

The veteran Northern Ireland journalist David McKittrick has told BBC Radio 4's PM programme that "the atmosphere is really very poisonous between Sinn Fein and Arlene Foster's Democratic Unionists," and that meant another election was "coming down the line" in Northern Ireland.

Outgoing First Minister Arlene Foster says she is , externaldisappointed" that Martin McGuinness had chosen to take the position he had by resigning.

"His actions have meant that, at precisely the time we need our government to be active, we will have no government and no way to resolve the RHI problems. It is clear that Sinn Fein's actions are not principled they are political," she said. 

Sinn Féin MLA Conor Murphy tells BBC's Evening Extra programme that Martin McGuinness's decision to step down was "not drastic, but very much calculated".

He said the DUP and Arlene Foster have become "even more bullish" since Christmas. "The only option now is to go back to the electorate," he said.

Northern Ireland Secretary of State James Brokenshire says the British government will do all it can to "help the parties find a resolution in the coming days".

“There is a clear process set out regarding what happens next," he said. "Unless Sinn Fein nominates a replacement to the position of deputy first minister within the next seven days, it is incumbent upon me to call an assembly election within a reasonable period."

“I would urge Northern Ireland’s political leaders to take the necessary steps to work together to find a way forward and I will work with all parties and the Irish government to this end.”

Now that Martin McGuinness' resignation has taken effect, under the joint protocols that govern Stormont's power sharing government, First Minister Arlene Foster also loses her office.

She may continue to exercise some functions, but her role will be very limited. Sinn Féin has seven days to nominate a new deputy first minister following Mr McGuinness' resignation. However, the party is adamant it will not replace him.

Political correspondent Gareth Gordon has been pondering over what's next for Stormont? "It's always easier to tear things down than put them back up," he says.

Sinn Fein sources making it clear they will not come back to the status quo. So that being the case could we be heading for yet another of those tortuous negotiations.

Ulster Unionist leader Mike Nesbitt said the resignation of Martin McGuiness was "not the way to resolve the RHI scandal".

"Sinn Féin should have stayed, to hold the first minister to account, to force a public inquiry and to vote on the much-needed cost controls on the scheme," he said.