Strikes have not been ruled out after staff working on Nottingham's trams rejected a 1% pay rise.
Last week industrial action was postponed when talks between the GMB union and Nottingham Tram Consortium (NTC) ended with the new offer.
But the union now says the deal had too many strings attached.
The union is now seeking further talks with management - but has not ruled out out further walk outs. Managers at NTC have not yet responded to the news.
The union had sought a 5% increase but NTC rejected this saying economic conditions meant it faced a drop in income.