London Briefing:Chief executives come and go; some get fired because they are not up to the job, others have their fingers in the till and some just get up the noses of institutional investors.

It is now just over a week since Lord Browne of Madingley resigned as chief executive of BP after having been exposed as a liar in his attempt to cover up exactly how he met his young (former) boyfriend.

There are those - particularly Mail on Sunday executives, who paid handsomely for the kiss- and-tell story of Jeff Chevalier - who take a particularly hard line against lying to a court.

Most of us do, of course, although who could not also understand why Lord Browne preferred to keep secret the fact that he met his boyfriend through a gay website rather than, as he initially told the court, when jogging in Battersea Park?

He was wrong to accuse his former partner of drink and drug problems that could not be substantiated by medical records. As his detractors have made clear, it will be difficult now for Lord Browne to be trusted again in a court of law - how easy it will be for the opposing counsel to cast doubt on the peer's reputation for honesty.

Much is made of the liberalisation of society in recent years - was not Lord Browne's success a graphic demonstration of that? But gay men (and women) of his generation simply find it easier to gloss over their sexual preferences rather than have to become a flag-carrier for the gay movement.

The City of London is no better - and no worse - than the rest of the country in its treatment of minorities from Asians to blacks, homosexuals and lesbians, but - and this is where the Square Mile can hold its head up - when someone is good at their job, no one cares a jot about their sexual orientation.

Last week's dramatic fall from grace of the man who was known in the global oil industry as the "Sun King" sparked the usual knee-jerk comment about how impossible it is for a gay man or woman to break through the "pink plateau" that exists in today's business world.

Lord Browne gives the lie to that, as his sexuality was an open secret within BP and was also widely known within the media. He simply came from a generation that prefers not to discuss these things in public.

His disgrace in having being exposed as a liar has been received with remarkable equanimity in the so-called homophobic City of London. Last Saturday, at the height of his disgrace, scores of leading figures in Britain's arts, business and political establishments joined forces to praise the former BP chief executive.

The letter had 64 signatories, including financial heavyweights Sir Winfried Bischoff, chairman of Citigroup, and Sir Evelyn de Rothschild, key movers from the arts such as Gail Rebuck, chief executive of Random House, and Sir Nicholas Serota, director of the Tate gallery, and Labour peers such as Lord Puttnam.

They declared their full support: "We wish to place on public record our support now and in the future for our friend John Browne and to thank him for his immense and unique contribution to business, the economy and to art, culture and the environment."

The statement added: "We wish him well, stand by him and look forward to working with him in the years ahead."

In the meantime, Lord Browne has more than adequately demonstrated his character by the way in which he had handled the aftermath of the crisis.

Far from going to ground, as many might have expected, the BP boss chose to fulfil a long-arranged speaking engagement in Brussels less than 24 hours after the affair broke.

At the meeting in Brussels, Lord Browne vowed to put the events of the last few days behind him, saying that a person's identity was defined only in part by his or her "passions and personal relationships".

Lord Browne quoted Prof Sen's insight that any human being's identity is made up of multiple factors, pointing out that it was dangerous to frame people's identities by colour or creed. Factors that helped to define human identities included professional life, occupation and "our individual passions and personal relationships".

The former BP chief began his speech lecture with a rueful observation about the last few, tumultuous days: "It's a great pleasure to be back in Brussels and a great honour," he said. "The past few days have been testing for me personally. I'd like to express deep gratitude for all the enormous support I have received."

He was greeted with generous applause from the audience. In his speech, Lord Browne paid an emotional tribute to his mother Paula, who survived 18 months in the Auschwitz concentration camp. Like her, he said, he would now look to the future, not the past.

• Fiona Walsh writes for theGuardian newspaper in London