GMB national officer Justin Bowden said: "Southern Cross may be on its last legs but for Southern Cross's 31,000 residents and 43,000 staff this looks like a case of 'out of the frying pan, into the fire'.
His camp also has some hopes that the Scottish GMB might back him.
The GMB union described the closure as devastating.
Due to mergers, Unite, Unison and GMB represent three-quarters of the union section of the conference vote, making it very difficult for them to be defeated.
Bert Schouwenburg International officer, GMB We might get Thatcher more nearly right if we stopped trying to treating her era as a seamless whole.
Paul Kenny, general secretary of the GMB union, said: "This is just the same old Tories who are anti-trade union, anti-working people having a voice and anti-democratic.
John Edmonds, general secretary of the GMB union, says the same.
GMB, a trade union, unmasked such a case in March, it says: a Polish worker at a site in Kent was being paid £4 an hour less than the NAECI minimum.The PWD itself sets minimum standards, but they are not supposed to undercut national ones.
He can rely on the T&G and GMB, the two largest unions.
An opinion poll commissioned by the GMB suggests that people agree that the public sector should remain public; other recent polls suggest that private provision is acceptable to most.
Lack of such transparency was one shortcoming identified by a report after the first Lindsay strike, by the government-sponsored Advisory, Conciliation and Arbitration Service.Early in June GMB and Unite, two big unions, said they would poll around 25,000 workers at 100-odd sites on whether the impasse justified strike action.
