SEX and politics has really only one rival for headline-grabbing at Westminster: money and politics.

In 2010, David Cameron proved the power of irony is never understated when he admitted how the next big scandal to hit Westminster would be over lobbying or, as he put it, the “far too cosy relationship between politics and money”.

Sure enough just weeks later, Stephen Byers, the ex-Labour transport secretary, was caught on camera foolishly telling an undercover reporter that, once out of government, he was like a “cab for hire”, boasting: “I still get a lot of confidential information because I'm still linked to No 10.”

Fast-forward 11 years and Mr Cameron had clearly forgotten his prescient remark and has become caught up in a web of deepening controversy that could well leave an indelible stain on his reputation; indeed for some, it already has.

Lobbying is, arguably, the second oldest profession.

Putting your case to those in power to further a particular cause is the daily stuff of politics. However, there have to be rules, strict rules, so those who govern us are not unduly influenced by malign forces.

Companies, of course, like the kudos of having an ex-senior minister on their books.

They believe it impresses others and, when the time comes, may give up some useful inside intelligence or, as in the case of Mr Cameron – who insists he has not broken any rules on lobbying – a handy hotline to Downing Street.

One of the many surprising aspects about what has now been branded a scandal is that the former PM, a multi-millionaire before, during and after leaving office, felt the need to work for Lex Greensill at all.

But, clearly, the prospect of trousering an extra £20m in share options working for a former No 10 aide in his finance company was too good an opportunity to miss.

Back-scratching, it seems, has become a lucrative art form.

The problem with ministers becoming lobbyists is, post their time in government, a suspicion always lingers that during their final months in Whitehall their focus was not on the public job in hand but on the private one to come.

It would be shameful enough if this sorry saga was just about an ex-premier trying to line his pockets but the collapse of Greensill Capital could well lead to thousands of people losing their jobs in the steel industry.

Founded by the Australian financier, the company specialised in supply-chain finance, settling business bills immediately for a fee and so helping eliminate the problem of late payments.

Indeed, in 2018 Greensill won a £30m contract from the Cabinet Office that gave pharmacies the option of being paid early for NHS prescriptions.

Astonishingly, it has now emerged that Bill Crothers, a former top official responsible for overseeing billions of pounds in the UK Government’s commercial contracts, was employed by Mr Greensill part-time while still working in Whitehall.

He formally left in 2015 and subsequently became a director of Greensill, where he is said to have held a stake worth £5m.

Now, Simon Case, the Cabinet Secretary, has issued an urgent demand that any moonlighting civil servant should come forward. This, incredibly, suggests the head of the civil service has no idea what might be going on in the workforce he runs.

Politically, Lobbygate has come just at the right time for the UK Government’s political opponents as people consider who to vote for in a raft of elections in Scotland, England and Wales.

Keir Starmer clearly relished announcing to the nation that our old friend Tory sleaze was back and during PMQs sought to connect the dots to a web of Conservative cronyism.

The Labour leader even managed a witty reference to the BBC’s popular crime drama Line Of Duty, telling Boris Johnson: “The more I listen to the Prime Minister, the more I think Ted Hastings and AC-12 is needed to get to the bottom of this one.”

Labour’s attempt to get a fully independent inquiry to take a comprehensive look at lobbying was always set to fall foul of the Commons arithmetic. Yet House committees are now falling over themselves to probe the subject, which must be causing nerves to jangle in Tory circles at Westminster and beyond.

Whatever the Government-appointed lawyer Nigel Boardman recommends in June must command public confidence and support. The current system clearly has too many holes and needs a substantial overhaul; otherwise we will be back here yet again in a few years’ time.

Voters must feel they can trust not only those who govern them but also the systems of government.

The wily ex-minister Lord Pickles, who chairs the toothless Advisory Committee on Business Appointments which advises ex-ministers and civil servants on outside employment, told MPs yesterday, with a deal of understatement, there were “anomalies” in the system that required “immediate address” and that the Crothers’ case showed there did “not seem to have been any boundaries at all”.

Conspicuous by his silence in this whole affair is Mr Greensill. Will he, like Mr Cameron and Chancellor Rishi Sunak, offer to place place himself under the parliamentary microscope? He should.

Yet for all Labour’s understandable outrage at what they brand Tory sleaze and cronyism, they should know occupying the high moral ground carries a health warning as all politicians live in glasshouses and while today one party might be lobbing stones, tomorrow they might be on the receiving end.

Now that several official inquiries are under way into various aspects of Lobbygate, more shocking revelations could well lead us all to experience one or more of Ted Hastings’ memorable “Mother of God” moments.

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