The leaders of the five main political parties in Northern Ireland have pledged their support for the chief constable, days after the shooting of a senior officer.

Dissident republican group the New IRA are suspected of involvement in the attempted murder of Detective Chief Inspector John Caldwell at a sports centre in Omagh, Co Tyrone, on Wednesday night.

He had been putting footballs in the boot of his car with his young son when two gunmen fired a number of shots at him.

Mr Caldwell remains critically ill in hospital and is heavily sedated.

The five Stormont parties issued a rare joint statement condemning the attack on Thursday.

On Friday, leaders met Simon Byrne at police headquarters in Belfast before standing shoulder to shoulder with him for a press conference.

Sinn Fein vice-president Michelle O’Neill, DUP leader Sir Jeffrey Donaldson, Alliance deputy leader Stephen Farry, UUP leader Doug Beattie and SDLP leader Colum Eastwood took part in the joint press conference with the chief constable, who hailed the importance of the act of political unity.

“We echo our thanks because it has rippled through the organisation about how important it is that we’re joined by the political leaders today at this unique time to show that we stand together and call out this outrage for what it is,” Mr Byrne said.

Northern Ireland Secretary Chris Heaton-Harris welcomed the meeting, saying it “shows that all of Northern Ireland is united in not returning to the violence of the past”.

He said he spoke with Mr Byrne, and pledged his and the UK government’s support for the PSNI.

Ms O’Neill emphasised the importance of unity in the wake of the attack.

“We do stand here united as one voice in our condemnation against this horrific attack on a police officer, someone who is part of our community,” she said.

“I think that the most powerful message that we, as political leaders (can do, is) to stand with the chief constable today, to stand with the police service and say, this is not good enough.

My cousin was the first RUC officer to be murdered by the IRA in 1970. Loyalists have also killed police officers. It was never acceptable and it is not acceptable now

“This is an attack on all of us, this is an attack on our community.”

Sir Jeffrey warned: “I would say to the evil people who carried out this heinous attack and to their organisation – you are not the future of this place. We stand against you.

“The murder of police officers and the attempted killing of those who serve our communities in Northern Ireland is unacceptable.

“My cousin was the first RUC officer to be murdered by the IRA in 1970. Loyalists have also killed police officers. It was never acceptable and it is not acceptable now.

“It will not be tolerated and we stand foursquare with the police to ensure that those who have been responsible for this attack are brought to justice and that they do not dictate how this place moves forward in the future.”

Mr Farry said all five parties are “standing shoulder to shoulder with the chief constable and all of the brave men and women of the Police Service of Northern Ireland”.

“All five parties are utterly united in rejecting terrorism and standing up for the rule of law,” he said.

“We are determined that those responsible will be brought to justice and that police have the resources they need to do their job properly.”

Mr Beattie said the attack on Mr Caldwell was an attack on Omagh, our society, peace and the Belfast/Good Friday Agreement.

“But it will not work because we do stand united,” he said.

“We will ask our society to do similar, raise their voices against these people and say, you do not belong here, what you stand for does not represent us, you will not undermine what we achieved in the last 25 years for your own vile, depraved ends.

“We will overcome this.”

Mr Eastwood said those who carried out the attack “represent nobody and will achieve nothing”.

“They think they are at war with the British state, they’re at war with the people of Ireland, from my perspective, that is a battle they will never ever win,” he said.