The following piece of mine appears in today's Dail Mail:

Has there been a more embarrassing, depressing and, indeed, shaming spectacle in recent memory than the sight of Margaret Beckett representing our nation in response to the abduction by Iran of 15 British sailors?

There will not be many people who seriously challenge the claim that Mrs Beckett is the most hopeless Foreign Secretary of the modern political era. Not only is she incompetent, but she is almost entirely unprincipled. And it is that combination which makes her the ultimate, shameless symbol of politics today.

Indeed, the only principle that Mrs Beckett has unswervingly championed in her 30-year career in frontline politics has been her own desire for high office.

To that end, she has let nothing come between her and the advancement of her career within the Labour Party, both in government and opposition. Yet if she had an ounce of personal insight, she would no longer be in the Cabinet, let alone Foreign Secretary at a time of grave crisis.

Yesterday, the Environment, Food and Rural Affairs Select Committee delivered its withering verdict on the chaotic way, in her prvious cabinet post, she handled the payment to farmers of £1.5 billion of EU ‘green’ subsidies. Failures in a new computer system led to a fiasco that could ultimately cost Defra and British farmers up to half a billion pounds.

Select committees are usually judicious in their language, especially when commenting on a member of their own party. But so appalling was Mrs Beckett’s behaviour that the Labour-dominated committee could not contain its anger, which it directed personally at her.

In an unflinching attack, it accused her of being prepared to accept 'the glories' of high office without any commensurate acceptance of personal responsibility. Unanimously, the members found that saying 'sorry' was not enough and that, far from being promoted to Foreign Secretary, she should have resigned over her 'embarrassing failure'.

Typically, Mrs Beckett did no such thing; nor will she now. Because, as her career shows, the notion of any guiding principle other than the advancement of her own career is entirely alien to her.

Mrs Beckett – Margaret Jackson, as she then was – entered Parliament in 1974. A committed left-winger – her reputation was borne out by her initial behaviour as a member of the hard-left Campaign Group. She was a vociferous supporter of Arthur Scargill in the miners’ strike; she opposed expulsion of the Militant Tendency; she was a full-on nuclear unilateralist.

Mrs Beckett embraced the full package of left-wing principles. Or rather, she professed to embrace them when it suited her career.

But when an opportunity arose for promotion, she ditched both her principles and her comrades.

She had been in the Commons for less than two years when, in 1976, she exploited a left-wing colleague's resignation as a minister over spending cuts and jumped at the chance to replace her. This blatant U-turn in the pursuit of personal glory was soon followed by others.

She lost her seat in the Conservative landslide of 1979. Looking for a new seat at a time when only the purest of left-wingers could win selection, she conveniently regained her old principles. In 1981, she attacked left-wing MPs such as Neil Kinnock for failing to vote for the radical Tony Benn as Labour’s deputy leader - leaving the more moderate Denis Healey to win the post. Beckett told Kinnock that he should contribute 'thirty pieces of silver' to the Tribune Group of left-wing MPs for his treachery.

So what happened when Kinnock later became party leader? Surprise, surprise, Mrs Beckett performed yet another about-turn, accepting a series of Shadow Cabinet jobs. Most outrageously, she later resigned from the Campaign Group when it backed a leadership challenge by Tony Benn. Once again, Mrs Beckett’s supposed principles were swiftly despatched when they stood in the way of her career.

I experienced Mrs Beckett’s double standards for myself when I worked for a principled Labour MP, Peter Shore. He was heavily involved in an organisation comprising Labour members who had opposed British membership of the then European Common Market.

Mrs Beckett was a supporter of the group and even placed a personal ad in some campaign literature offering warm wishes.

Yet at the very same time, she was also an unwavering backer of the Kinnock line on European federalism, and later of his successor John Smith’s embrace of the European Monetary Union.

The sheer hypocrisy of her behaviour did not appear to bother her in the least. She showed similar hypocrisy in 1993, sensing that the trades unions were likely to beat off the party leadership's refoming bid to introduce One Member, One Vote into Labour party conference votes, in place of the union block vote.

Despite having become Labour Deputy Leader, she deftly stabbed her boss, John Smith, in the back by refusing to pledge her support for the critical reform on which he had staked his whole leadership. In the end, it was John Prescott who had to ride to the rescue and plead with the unions to support the leader. Mrs Beckett, after all, had her career to consider.

Even by the standards of modern politics, such blatant hypocrisy is breathtaking. Tory leader David Cameron is regularly referred to as a careerist. But he is a mere apprentice opportunist compared to the woman who sits opposite him on the government bench in the House of Commons.

Nothing says more about the dismal standard of our political system than the ongoing career success of a talentless, incompetent, unprincipled MPs like Margaret Beckett - who, incidentally, exclaimed: 'Oh, f*ck!' when Blair appointed her as Foreign Secretary.

At a time when we have a captured British servicewoman paraded on television by a foreign power, we need politicians of courage and conviction to make a stand on the global stage. Instead we have empty platitudes and spineless reassurances from a woman whose utter incompetence is now a matter of official record.

Margaret Beckett’s presence in the upper echelons of government is a disgrace and a national scandal.