Chancellor Angela Merkel faces a divide within her ruling Christian Democratic Union party, over tax reliefs for gay couples, which have so far been reserved for married, straight, couples.

At the conference in Hanover, delegates are expected to re-elect Dr Merkel for a 13th year, however she is seemingly caught between a conservative party front, and a more progressive one, reports the Irish Times.

Aware of the schism within her party, and the looming 2013 general election, the party leader has opted to vote in favour of preserving these tax perks for married straight couples.

The progressive CDU members want to extend tax perks currently only received by straight, married, couples to gay couples as well.

This would include the “spousal split” rule, which means that a couple’s earnings are pooled, and divided equally, in order to determine each person’s taxable income.

It is believed by a dozen backers of the move, and many younger leaders in the party, that this change could help reverse a decline in support for the CDU in urban areas.

The conservative CDU front, however, argues that this change would further Dr Merkel’s move to the political centre, and that she has sacrificed the Christian values, and conservative identity of the party.

An alternative motion has been drafted by such party members, which expresses “respect for those who realise their lives in a different form of partnership”, which is against discrimination and intolerance, but would reserve the tax relief for married couples.

The German constitution currently guarantees “particular protection of the state” to family and marriage, however recent court rulings have utilised another constitutional right – equality before the law – to close several remaining legal gaps between marriage, and the country’s 2001 same-sex partnership bill.

Alowance priveleges for straight civil servants over gay colleagues were struck out by the court, as well as pension tax laws which distinguished between gay and married couples.

In several rulings, the court said it did not see how marriages would be downgraded by offering fiscal perks to same-sex couples as well, and questioned the validity of tax perks for married couples without children.

A constitutional court ruling on the issue of the tax perks is expected some time in 2013.

Thomas de Maiziere, an ally of Dr Merkel’s, and federal defence minister, said he did not think the current system of tax perks would survive the court ruling.