Sinn Féin has condemned the announcement of a new and more accurate plastic bullet for the RUC and army in Northern Ireland and police forces throughout the UK.
British Home Secretary Mr Jack Straw announced the new round would be available for crowd control duties from June 1st, but Sinn Féin said they should be banned immediately.
"Any other approach is unacceptable," said Mr Gerry Kelly, party spokesman on policing.
It appeared the issue could become another condition imposed by Sinn Fein in return for its backing for policing changes in Northern Ireland.
However Northern Ireland Secretary Dr John Reid said the government was carrying forward the recommendations of the Patten Report on policing change in Northern Ireland which said there should be investment in research into finding an acceptable, less dangerous, alternative to the present baton round.
He said the government would be delighted if the public order situation in Northern Ireland improved sufficiently to remove the need to resort to baton rounds at all.
"The whole community has a contribution to make to achieve that aim, but sadly we are not there yet," he said.
But Dr Reid said the government would ensure every effort was made to find an alternative and to provide the police with a broader range of public order equipment.
"We will continue the search for a safer alternative, but meanwhile we have introduced a round that independent experts have concluded is, on balance, a great deal safer than the existing one.
"Our objective remains the same: to reach the position in which the need to use baton rounds will ultimately disappear."
But Mr Kelly said: "There can be no equivocation on this issue. Plastic bullets have to be banned from use."
He indicated it would be another issue on which Sinn Féin's support for the new policing service being constructed in Northern Ireland would depend.
"Any police service that trains its personnel in the use of this weapon or is prepared to use it cannot expect to win the support of nationalists and republicans," he said.
PA