Ian Lawrence, national officer with the Public and Commercial Services union, Inland Revenue, described the plans for the call centre in Newcastle (due to open in April) and the additional staff who will operate it as a 'very positive step' and said the union was 'very hopeful'.

But he urged the Revenue to ensure that new staff being hired were 'fully trained' and had access to the 'necessary facilities' to meet public demand.

Last September, the PCS threatened to strike over the tax credits fiasco, but Lawrence said it was too early to say whether the threat of such action had been reduced by this latest step.

But he reassured: 'We will not seek industrial action just for the sake of it.'