UK performers union Equity has pledged to support the threatened strike this summer by the Screen Actors' Guild (SAG).

The move, which was expected, means Equity will advise its members not to accept work on runaway productions - that is US productions that are shooting in the United Kingdom after 31 June in an attempt to avoid or undermine the strike.

"The potential dispute in Hollywood comes at precisely the same time as British Equity is looking for a radical review of our films agreement," said general secretary Ian McGarry in a statement issued Tuesday. "Actors on both sides of the Atlantic are united in feeling that the time is right for a breakthrough in the way that actors share in the success of a film."

McGarry added that Equity is in discussions with SAG about its recently published guidelines regarding how they affect British performers working in the UK on non-runaway productions. According to SAG guidelines issued last month, non-US nationals can appear in non-US financed projects shooting outside the US even if they are SAG members.

That could play into the hands of well-financed non-US companies such as Intermedia, FilmFour or StudioCanal which are able to greenlight up to a certain level without US financing. UK and US-based financier and sales agency MM Media Capital Partners is preparing David Cronenberg's Spider, starring UK actor Ralph Fiennes, for a summer shoot.

But further clarity about SAG's guideline's would be widely welcomed. Some fear that high-profile non-US SAG members will not want to risk being seen as strike breakers by appearing in even local productions. Either way, McGarry added that any dispute in the US will have a major impact in the UK as US productions shooting here dry up.

"American productions that might otherwise have come to the UK to use studio facilities or for location work would undoubtedly stay away," he said. "Clearly such films are dependent on American star participation and if that is not available those productions, which normally provide a significant amount of work for British-based talent, will not take place."