Talks between unions and the Cabinet Office are expected to conclude at the end of the first week in March, rather than late February. If this revised timetable is kept, a special executive meeting on March 15 will consider the final package.
The next day, on Friday March 16, reps from all 91 civil service branches are invited to a consultative forum in London, to assess the proposals and express their views. After that, any final package will be put to an all-members' ballot.
But Prospect deputy general secretary Dai Hudd said: "As in the other public sector scheme discussions, delays by the Treasury are hampering progress in arriving at a final package for the civil service.
"These gaps must still be resolved before we can ask the executive to take a view on any final package.
"Nor can we ballot members without a clear, definitive line on certain key elements within the new scheme."
There has been no movement from the official side on the higher pension age; increased contribution rates; and the introduction of a career-average scheme. Separately Prospect and other unions are awaiting a judgement on the CPI uprating issue in the Court of Appeal.
Prospect does not oppose the principle of a career-average scheme, as long as the accrual rate is right. It is seeking a rate of 1/43rds, as in the existing Nuvos scheme. This would mean that, depending on when they retire, members could receive pension benefits at least as great as their current entitlement.
The Cabinet Office has also agreed to strengthen the 'Fair Deal' protection for members transferred to the private sector.
On other issues, unions including Prospect are still awaiting the Treasury pay remit guidance before negotiations on pay 2012 can begin. Because of the 1% pay cap which will follow the two-year pay freeze, the union has commissioned market research from Incomes Data Services to reinforce the Prospect case on specialist pay.
Prospect is also preparing a new vision document on the future of the civil service and the importance of specialists and professionals for effective government, which will be launched next month.
That will be followed in the summer by a 'Cuts that Hurt' campaign highlighting the impact of the government's policies on individuals, communities and the nation.