It will be a great mistake if the inquiries being held into George Osborne’s decision to become editor of the London Evening Standard while remaining an MP come to the conclusion that further restrictions should be placed on the ability of MPs to hold second jobs.

The reason is that such a decision would further strengthen what has come to be called the “political class”. The mark of the political class is that its members only know politics, having, generally speaking, never been employed outside the Westminster village. It comprises MPs and all those who support them in their work – political consultants and advisors, research assistants, staff at party headquarters, in the House of Commons and in policy research institutes tied to the political parties. Many of these aides expect to become MPs themselves in due course.

A political class was first created during the 1980s. Before that politics was very different. In his autobiography, Kind of Blue: A Political Memoir, Ken Clarke, the Conservative politician, recounts how when he arrived in the House of Commons in 1970, it was essentially a large political club where most MPs would gather in the afternoon and then stay into the evening and often the night in close proximity with each other. Dining clubs were another prominent feature.

He goes on to describe how the composition of the House was also far removed from that of today. “There was a marked class divide between the two parties with many establishment and country-gentlemen-type characters on the Conservative side, and many working class and trades union Members on the Labour side.”

George Osborne defends appointment as editor of the Evening Standard

Looking back, Douglas Hurd, who was Foreign Secretary in the early 1990s, added an important detail: “In those days there were no jobs for passionate, ambitious politicians in their twenties … there were no bottom rungs on the political ladder.” He finally entered Parliament in 1974 aged 43.

From the 1980s onwards, however, new opportunities were created for politically ambitious young people to get into politics. At the time it wasn’t to be known that this would lead to the creation of a political class. There were three parallel initiatives: the creation of numerous think tanks that offered jobs for the politically minded; an increase in the allowances of MPs that enabled them to employ research assistants; and the further development of the role of special advisers to government ministers.

Three decades later, a Smith Institute study, Who governs Britain?, showed that 25 per cent of the MPs elected in 2015 had previously worked in politics as defined above. If you add the 10 per cent who had been in the media (from whence came Boris Johnson and Michael Gove), the 8 per cent who had a PR and marketing background, and the 6 per cent who were previously trades union officials, then it can be seen that virtually half the House of Commons is controlled by the political class.

Peter Oborne described them in caustic terms in his book The Triumph of the Political Class. He wrote that the political class has evolved two novel methods of communication, both of which estrange its members from the voters they are supposed to represent.

The first is the kind of language used when they talk among themselves. This has become arcane, always self-referential, often concerned with the techniques of voter manipulation and relying on the anti-democratic assumption that there are matters which ordinary people are either incapable of understanding, or which it would be too dangerous for them to know. The second is more familiar: the soundbites used to address voters, “artfully constructed sentences which create in the mind of the hearer the impression of being easy to understand, but which are designed to mislead”.

However there is an even greater difficulty than this. Members of the political class are completely unfitted to become government ministers and run the large organisations that are government departments. For politics had gradually become a trade rather than the club that it was when Clarke first became an MP in 1970. It is not a profession for it requires no formal qualifications and neither is it subject to a disciplinary body. Unlike working in business, no leadership skills are required.

Tony Blair endorses George Osborne's appointment as Evening Standard's editor

The consequences are best illustrated by a series of interviews with former ministers that have been conducted by the excellent Institute for Government. Take these remarks by John Healey on becoming minister for housing in 2009, for instance: “I had no training beforehand, no training after, no support after and I had a big, fat lever-arched file prepared by the department for new ministers, which I never got to read. I had no brief from the Prime Minister when he gave me the call to appoint me to the job.”

Listen now to Lynne Featherstone, who was appointed as a Home Office Minister with responsibility for criminal information and equalities in 2010, before being promoted, in 2012, to minister with responsibility for international development. She told the Institute for Government: “I literally didn’t have a clue. I didn’t even know what a submission was. Literally nothing.”

Finally Steve Webb, who was the minister of state for pensions in the coalition government led by David Cameron. He said that “sometimes I would write ‘yes’ on a bit of paper and things would happen, which was a bit of a revelation.”