In the coming days, the British government will have to consider whether the Loyalist Volunteer Force (LVF), which murdered the leading loyalist, Richard Jameson, in Portadown on Monday night, has broken its ceasefire.

Particularly, it will have to decide whether the 30 or so LVF prisoners, who are benefiting from the early-release programme, should be returned to the Maze Prison to serve their full sentences.

Several of the LVF prisoners are on life sentences and could potentially be facing lengthy terms in prison. The return of such a large group of prisoners could have a seriously destabilising effect on the security situation in the North.

It would almost certainly be accompanied by protests and violence from the LVF's supporters, who are spread throughout loyalist areas.

The LVF prisoners were included in the early-release programme last year after the group declared a ceasefire and handed over a number of antiquated and home-made firearms. These were destroyed in a public display in 1998.

Although there was a great deal of publicity about the apparent benign implications of this decommissioning act, some loyalist sources described it as a cynical ploy to gain early release for LVF prisoners.

Subsequently the LVF returned to carrying out sectarian attacks on Catholic homes and businesses. An LVF pipe bomb killed Mrs Elizabeth O'Neill, a Protestant married to a Catholic, in Portadown last June.

The British government may, however, interpret Mr Jameson's death as part of a long-standing row between the LVF and UVF in Portadown. This has been going on since 1996 when the LVF, led by the extreme figure, Billy Wright, emerged in Portadown.

It erupted again at Christmas when there was a major fracas between the two sides in a local social club on December 27th.

If no official sanction is taken against the LVF, pressure could be increased on Jameson's associates in the UVF to take matters into their own hands.

There is undoubted pressure on the UVF to retaliate. It is the dominant loyalist paramilitary force in the North but faces challenges within the loyalist community from dissident anti-agreement groups.

Some of the opposition to the UVF is also from former loyalists who have moved into the drugs trade.

If the UVF fails to retaliate against the dissidents for the Jameson killing, it will lose face, particularly among the younger militants in the loyalist community. If it does retaliate, the UVF, too, would be in breach of the Belfast Agreement.

It may jeopardise the early release of its prisoners as well as creating a number of new felons who might be involved in murders or murder conspiracies.

This scenario would be a serious blow to the peace process.

The UVF, of which Jameson was a leading member, has so far adhered quite closely to the peace process and the Belfast Agreement.

Despite carrying out punishment beatings and shootings, it has refrained from any aggressive acts against republicans or, for that matter, other loyalist organisations since October 1994.

It is, in fact, the only paramilitary or terrorist organisation in the North not to have seriously broken its ceasefire in the intervening years.

On the loyalist side, there are residual concerns about the activities of the other main paramilitary organisation, the Ulster Defence Association (UDA).

The LVF and the UDA have been in cahoots in recent years. The UDA was responsible for supplying the car-bomb which killed Ms Rosemary Nelson in March last year.

The Nelson killing was cynically designed to cause destabilisation of the peace process. Ms Nelson was the legal champion of the nationalist residents of Garvaghy Road in Portadown.

Her murder was designed to heighten tension in the area before last year's Orange marching season.

As it happened the UVF, Orange Order and pro-agreement unionist forces combined to avert any disruption over the demands of the Drumcree Orangemen to walk down Garvaghy Road and the summer passed off peacefully.

The killing of Richard Jameson is being interpreted by pro-agreement loyalists as not only an attack on the UVF, but on the whole process. They argue that the people responsible for the Nelson and Jameson killings have consistently pursued an anti-agreement line.

It is often not appreciated that the loyalist dissidents are as strongly opposed to David Trimble's moderate leadership of unionism as the republican dissidents of the "Real" IRA and Continuity IRA are opposed to the SDLP and Sinn Fein leadership of Northern nationalism.

It is also, possibly, not a coincidence that the Jameson killing has come at yet another critical point in the peace process when there is hope that the Provisional IRA is on the verge of decommissioning weapons in order to facilitate the continuation of the Northern Assembly.