The pledge marks a four-week extension to the current provisions and would double paternity leave to two weeks.

The $7million plan over four years brings the ACT public service into step with recommendations outlined last week by the Productivity Commission for an Australia-wide system.

Chief Minister Jon Stanhope said the move put the ACT ahead of the Federal Government, all the states and the Northern Territory.

This view was backed by the Community and Public Sector Union yesterday.

A union spokesman said other jurisdictions provided 12 to 14 weeks' leave.

Mr Stanhope said the provision was a step towards a long-range target the Government supported 26 weeks' paid leave.

''We understand how implicitly important it is to invest in our workforce,'' the Chief Minister said.

''Taking paid maternity leave to 18 weeks once again shows my Government and the Labor Party and the ACT leading the way.''

The pledge received support from Liberal Leader Zed Seselja. The Opposition Leader would not say whether his Liberals had planned a similar announcement or whether it had included the policy in their costings.

He said the policy was in line with other Liberal promises aimed at reducing the strain on families in the territory.

''We wholeheartedly support it: we believe it's a good policy and it's a natural next step in helping women, in particular, in balancing work and family,'' Mr Seselja said.

''We're spending less than the Government and that's clear, and we have costed all of these issues: we're very comfortable with our spend and we're prepared to support good policy.''

Minister for Women Katy Gallagher said she hoped the policy, which would come into effect on July 1 next year, would aid the recruitment and retention of staff.

''This will go a long way to retaining and attracting new workers to our workforce, which is something we always have to look at when we compete with the Commonwealth public sector.''

CPSU deputy national secretary Nadine Flood said the scheme would make the ACT competitive with the private sector, federal public sector and universities.

''We think it will make some women consider moving to the ACT and encourage women to stay within the system who are contemplating having kids,'' Ms Flood said.

''We'd certainly encourage all of the major and minor parties to fall in line with the proposal ACT Labor has put forward.''

Mr Stanhope said he hoped the private sector would follow the Government's lead to make the ACT a more attractive destination for workers.