The Taoiseach, Mr Ahern, has been criticised by campaigners today who claimed he was attempting to suppress protests against a state visit by President George Bush.
The United States leader will be in Dublin for two days in June to meet Mr Ahern in his role as president of the EU, but plans to advertise an anti-war protest have been thwarted by the Government.
The Irish Anti-War Movement said the ban on posters promoting the demonstration was a serious attack on basic civil liberties.
Dublin City Council has refused permission to put up the posters following an amendment to legislation passed in the Irish parliament last year which bans the use of posters for public protests or meetings without permission from the local authority.
At a meeting attended by members of the Labour party, Sinn Fein, the Green Party and representatives from the Irish Council for Civil Liberties and the NGO Peace Alliance the move was described as "cynical and draconian."
The coalition vowed to defy the ban and advertise the protest, planned for March 20, against occupation in Iraq as well as the forthcoming visit by president Bush.
They said they would fight any fines incurred for littering in the courts. Richard Boyd Barrett, from the Irish Anti-War Movement, said the Government was deliberately trying to prevent a repeat of last year's protests against the war on Iraq.
John Gormley, Green Party foreign affairs spokesperson, said this was not about litter but censorship.
"Quite simply, the Government and the City Council don't like the anti-war message and this must be seen as an infringement of civil liberties," he said.
Mr Ahern has already asked people not to protest against President Bush's visit.
A massive security operation will be put in place to safeguard his meeting in Dublin on June 25-26.
The meeting has been called in an attempt to improve relations between the EU and the US.
PA