A former Prime Minister has for some years played a significant paid advisory role for a secretive Washington DC-based private equity firm with annual revenues of over $4bn. The Carlyle Group has also signed up an impressive list of former US politicians including President George HW Bush; and until 2005 its chairman emeritus was a former CIA deputy director, Frank Carlucci. Carlyle, perhaps not coincidentally, has made highly successful forays into the armaments business, such as its purchase of a controlling interest (since sold) in United Defense, supplier of vertical missile launch systems.

The ex-Prime Minister in question is John Major – which perhaps explains why no one has been jumping up and down to complain about the former Tory leader's joining commercial forces with his old friend from the White House, and giving Carlyle the benefit of the many useful contacts he had made while at 10 Downing Street. That's not the only reason, I hasten to add – there's also nothing improper about this arrangement; but the main reason for this being a non-issue is that John Major is not a man about whom the British public has very strong feelings.

The same cannot be said about Tony Blair. To say that he is hated – by a vocal minority – would be a gross understatement. The word "hate" does not do justice to the violence of this minority's gibbering rage at even the fact of his continued existence. Thus it was a shrewd move of Channel 4's Dispatches to commission the indefatigable Peter Oborne to make a documentary about Mr Blair's globe-trotting business dealings – and to question if there were conflicts of interests with his other role as representative of the Quartet of the US, Russia, Europe and the UN in their efforts to bring about peace between Israel and the Palestinians.

Oborne's programme, broadcast last night, investigated Blair's success in persuading the Israeli government to open up radio frequencies so that the Qatari-owned phone company Wataniya Mobile could operate in the West Bank. According to the programme, this boon to the inhabitants of the West Bank is tainted because the US investment bank JP Morgan had made a $2bn loan to Wataniya Mobile's parent company, and therefore stands to gain from Mr Blair's twisting of the Israeli government's arm – and Mr Blair has a paid advisory role with JP Morgan.

The response of Mr Blair's office was that the former PM had no idea about JP Morgan's link with Wataniya Mobile, and that "Tony Blair has advocated for the Wataniya project at the direct request of the Palestinians... [it] represented the largest single direct foreign investment into the Palestinian Authority". His office added that claims of a conflict of interest were "defamatory".

Of course, that won't make the slightest impression on Mr Blair's critics. If he were to bring peace between Israel and the Palestinians (a remote prospect, admittedly) they would regard such an outcome as blighted simply by virtue of his involvement. This was evident in the reaction to Mr Blair's giving the £4.6m proceeds of his memoirs to the Royal British Legion. This newspaper's Yasmin Alibhai-Brown described it as "cynical and provocative... chequebook expiation, kill and pay", while the Daily Mirror's Tony Parsons much less elegantly declared that "Blair should amputate a limb and give that to the British Legion".

There is no doubt that Mr Blair has, since his ousting from Downing Street following a putsch organised by Gordon Brown, made a lot of money, enabling him and his wife to accumulate a number of properties, worth – according to the perpetually-outraged Daily Mail – around £15m. It is one of the peculiarities of the well-remunerated Blairs' predicament that their new-found wealth is a cause of apoplexy on both the Right and the Left. Those on the Right tend to think that there is something inherently hypocritical if an ex-Labour Party leader makes a lot of money in retirement; they have no problem with John Major planning to buy a £3.5m Westminster apartment with the help of fees from the Carlyle group, or Lady Thatcher having accumulated a comfortable pile through making speeches in the US (before she became incapable). Yet if Mr Blair – or indeed Mr Brown – charges a large fee for speechifying in foreign parts, this is regarded as an outrage.

On the Left, the fury is for a different reason – although they also find the whole idea of people becoming rich as inherently unjust. They cannot forgive Blair for aligning the Labour Party with the forces of capitalism; and they regard his joining the Americans in the invasion of Iraq as nothing less than a war crime, for which he should be prosecuted at The Hague. The idea that Blair genuinely felt (however misguidedly) that Saddam Hussein did have weapons of mass destruction, is regarded as preposterous – although even Dr David Kelly, the unwitting source of the BBC's explosive assertion that Blair knew it was nonsense at the time, had agreed that Saddam retained biological weapons.

Y et it isn't necessary for people to believe that Blair is a mass-murderer in order to suffer from what Alex Massie in Foreign Policy magazine described as "Blair Derangement Syndrome". It is also an extension of the current mood of revulsion against politics in general – and Blair, having been the most popular politician of the era, must therefore become the most irrationally hated, once the infatuation wore off.

On a more human level, I can understand the ex-PM's frenetic combination of money-making and peace-mongering. His father suffered a catastrophic stroke at the age of 40 and Tony Blair himself has a dicky heart. It seems psychologically obvious that he feels he has not much time left to do everything he still wants to achieve – and he has always been ferociously ambitious.

In earlier years, when Prime Ministers left Downing Street at a more advanced age, such issues tended not to arise. By the time Jim Callaghan or Harold Wilson left office, they were ready for the gentle slopes of retirement, all passion (and ambition) spent. Yet Tony Blair and indeed Gordon Brown are still relatively young men with much to prove, not least to themselves. It is unreasonable to expect them to slink into obscurity; and if they strive to make their families financially secure, how does that harm us?

d.lawson@independent.co.uk