The Government will be in the High Court to defend the way it introduced the parental leave regulations this week.
The TUC has enlisted Cherie Booth QC to represent it in its challenge to the Government. It is claiming that restricting the right to three months unpaid leave to parents whose children were born after the implementation date is unlawful.
It believes that all parents with children aged under five should have become eligible to the time off when the law was brought in on 15 December last year.
Speaking about the challenge at the Achieving Work-Life Balance conference last week, TUC general secretary John Monks said, "The Irish government has, under EU pressure, been forced to change its course and we hope the Government will follow suit."
But Stephen Byers, the secretary of state for the Department of Trade and Industry, who jokingly referred to the case as Blair versus Blair, said he was confident that the directive had been interpreted correctly.
He added that business had lobbied hard for the right to be applied in a restricted way because it was worried about shouldering the responsibility for it.