The grant now payable is the equivalent of either one year’s average salary or the enhanced lump sum the teacher would have received if he or she had retired on health grounds - whichever is the greater. The average salary is the highest-amount paid for any successive 365 days during a teacher’s final three years of pensionable service.

From April 1, 1998, the death grant will be increased to two years’ salary - a move which will bring it into line with those already paid by the Civil Service, local government and most other public-sector pension schemes. In the private sector, death grants are often worth four or four-and-a-half times final salary.

Brian Clegg, assistant secretary of the National Association of Schoolmasters Union of Women Teachers, says the change is welcomed “in so much as this is bringing teachers’ death-in-servic e benefits into line with other people in local government employment. But we are complaining that the delay is unjustified and an immediate increase could easily be afforded.”

The doubling of the death grant is part of a package of changes to the Teachers’ Superannuation Scheme announced in February. Protesting about the delay in its introduction, teacher unions say that all the other changes, including those designed to cut the number of teachers taking early retirement, come into force this year.

The TSS allows married and single members to nominate a beneficiary to receive the grant. If a teacher is unmarried and has not nominated anyone, the grant will be made to the representative named in the grant of probate or letters of administration. In other words, the lump sum is paid into the teacher’s estate and can go to a legal spouse, other dependants or a common-law or same-sex partner.

By contrast, common-law and same-sex partners are barred from receiving the on-going pensions that teachers’ widows and widowers get on top of the death-in-service grant. An unmarried teacher can nominate a financially-dependent parent, brother, sister or widowed step-parent as the recipient of pension benefits. But the scheme explicitly states that a partner cannot be nominated.

The Trades Union Congress is campaigning to end this discrimination - which is common to all the statutory pension schemes and which affects about 217,000 public-sector employees cohabiting outside marriage, 38,500 of them teachers.

Public-sector employers have said that the cost of giving pension rights to unmarried partners would be too great. But according to the TUC - and the unions backing its campaign - the savings pension schemes are now making because of the fall in the number of married scheme members able to pass on widows’ and widowers’ pensions would more than meet the costs of introducing similar benefits for non-married partners.

Employers have also said it would be difficult to decide who would qualify for these benefits. The TUC has proposed setting a test for financial interdependency, with joint mortgages, bank accounts and other evidence of shared financial commitments providing proof that the relationship between the scheme member and his or her partner was a permanent one.

Many private-sector pension schemes already provide benefits for members’ common-law and same-sex partners. But unmarried teachers could have a long battle to give their long-term partners the same level of security. Brian Clegg believes it is unlikely that any government will be able to change the rules of the teachers’ pension scheme without also changing other statutory schemes.

“The present Government has been totally unsympathetic to that idea,” he says. “They tend to talk about people in the armed forces - who supposedly have a partner in every port - and therefore they don’t want to let anyone else through the loophole. Opposition parties have been more sympathetic. We await the results of the election with interest.” Judith Milroy and her partner Nick Smith had never seen any reason to marry. They had lived together since 1975 and always assumed that the money Nick paid into the teachers’ pension scheme would give them both financial security. It was not until Nick, a lecturer at Bradford and Ilkley Community College, died last year that Judith discovered she had no right to a pension.

Although their three children receive a pension payable until they reach 17 - or later if they continue in full-time education - and Judith received a death grant, she is far worse off than she would have been if they had been married.

She is angry not only about the relative financial hardship but also about the official refusal to recognise what had been a happy and long-term relationship.

“It feels like a denial of our relationship. It is almost as if they are saying that it never existed.”