Resilient Queen Elizabeth marks 60 yrs of marriage

LONDON, Nov 19 (Reuters) Even republicans admit they are fighting an uphill battle while Queen Elizabeth heads the House of Windsor.

Today, she becomes the first reigning British monarch to celebrate 60 years of marriage and with genes on her side -- her mother died at 101 -- and abdication out of the question, the abolitionists could be in for a long wait.

And what a difference a decade makes as the 81-year-old monarch and her 86-year-old husband Prince Philip mark their diamond wedding.

The monarchy's popularity plummeted in 1997 after Princess Diana, ex-wife of heir to the throne Prince Charles, died in a Paris car crash. Many Britons berated the royal family, feeling they had not shared enough in a public outpouring of grief.

Just 10 weeks after Diana's funeral, the queen was said to be so nervous about the public's attitude to her that she considered cancelling her traditional walkabout after a service to mark her 50th wedding anniversary.

She need not have worried.

''I thought that was the day the turnaround began,'' said royal biographer Robert Lacey. ''There was enormous warmth shown to her and Prince Philip as a couple.

''I think she has been underrated most of her reign. Only now are her qualities being appreciated,'' he told Reuters. ''For her it is clearly a job for life.'' CHARLES For this celebration she is returning to Westminster Abbey with her husband for a diamond anniversary service that retraces their steps up the aisle of the abbey in 1947.

The queen suffered a backlash from her children's disastrous marriages -- three out of four got divorced -- but most polls show support for the monarchy -- at least until she dies.

''The whole debate about the monarchy is on hold while the queen is able to pursue her functions,'' said Professor Stephen Haseler, chairman of Republic, which campaigns for an elected head of state.

''She is hanging on, as Charles is controversial and he will ignite the debate.'' Charles's tangled love life was sorted out in 2005 when he finally married his long-time lover Camilla Parker Bowles after a 35-year affair. Diana always blamed Camilla for the breakup of her marriage to Charles.

Even after decades of waiting in the wings, Charles's accession could pose problems for the monarchy.

''The institution of monarchy is in rude health as long as the queen is in rude health,'' said the Evening Standard newspaper's royal correspondent Robert Jobson.

''But there are big questions ahead. They will be over the suitability of Charles and Camilla, not necessarily in Britain but...in (Commonwealth) countries like Australia, New Zealand and Canada.'' REUTERS SYU BD1725