Tens of thousands of people are expected to take part in anti-violence rallies in the North today. The organisers said they believed there would be a massive turnout on the streets to demonstrate the community's opposition to paramilitary attacks and sectarianism.
Lunch-time rallies will be held in Belfast, Derry, Newry, Enniskillen, Omagh and Cookstown. Many businesses and services are expected to come to a standstill.
However, some shops, restaurants and taxi depots in Belfast have said they will continue to operate as normal.
The rallies have been organised by the Irish Congress of Trade Unions and follow loyalist threats against Catholic teachers and postal workers and the murder of Mr Daniel McColgan. The organisers decided to go ahead with the day of action despite the lifting of the threats.
Many unions have also called for a half-day stoppage. The rallies are supported by the four main churches and a range of business organisations including the Northern Ireland Chamber of Commerce, the Federation of Small Businesses, British Telecom, Translink and the Northern Ireland Civil Service.
ICTU's deputy assistant general secretary, Mr Tom Gillen, said he expected a massive turnout on the streets. "The day of action is an opportunity for the entire community in Northern Ireland to unite against terrorism and sectarianism. We must all show that we want an end to murder and threats." The success of the rallies would be measured if Mr McColgan's murder was the last one, he said.
The head of the Northern Ireland Civil Service, Mr Gerry Loughran, has asked departmental managers to facilitate staff attending the rallies but stressed that a presence still had to be maintained.
"For that reason, and while I understand and empathise with the aims of the trade unions on the issue of underlining total public condemnation of intimidation and violence, I cannot endorse the call for a half-day stoppage."
The Northern Ireland Ambulance Service and the Fire Brigades Union said they supported the rallies and arrangements had been made for staff to attend without affecting emergency services.
Translink is facilitating bus and rail staff who want to take part in the demonstrations.
Bus and train services across the North are expected to be curtailed between noon and 2 p.m. The National Union of Journalists is also supporting the rallies.
The leaders of the four main churches will either be present at the main demonstration in Belfast or else will send a representative. Presbyterian Moderator Dr Alastair Dunlop encouraged church members to attend.
"These rallies provide us with the opportunity to join with others in opposing threats to public servants, intimidation and racketeering, rioting and public disorder," he said.
"They also show our support for a society marked by co-operation, building confidence across divisions and replacing fear with trust."
The DUP said the need for a day of action exposed the failure of the Belfast Agreement.
In a statement to coincide with the rallies, the Church of Ireland Primate, Archbishop Robin Eames, said: "On this day from countless hearts and minds across Northern Ireland there is but one call: 'In God's name, stop this evil madness and let us find peace together'. "