Wrong target for Cameron

He fears that, despite the catalogue of own goals scored by the Labour government, the electors are still not ready to offer him and his party a free ride in the general election.

The gradually narrowing opinion poll figures have already forced the Tory leader to do a massive U-turn over his planned bonfire of public-sector jobs to pay for redemption of debts taken on to bail out the private financial sector.

He now pretends, if the Tories win the election, that the scale of cuts planned won't be anything like as drastic as he and his shadow chancellor George Osborne previously proclaimed.

Cameron's difficulty lies in the reality that most voters don't see a great deal of daylight between the policies advocated by both front benches, so he has to either make up differences or go ballistic over perceived variances.

After all, what were the massive issues that Cameron chose to fuel his broadside against the Prime Minister?

He urged him to withdraw the whip from three Labour MPs facing trial on dishonesty charges, which he knew was already in train.

Cameron accused Labour of providing free legal advice to the three men, which was categorically denied by the party.

The Tory leader accused Brown of blocking possible parliamentary reforms drawn up by a cross-party committee chaired by Labour MP Tony Wright only for Leader of the House Harriet Harman to reveal that a debate on the committee report is scheduled for a fortnight's time.

And he gambled on the public's short memory by suggesting that Brown is personally responsible for helping to create the parliamentary culture that has led to the expenses scandal and the rampant distrust of politicians in general.

So, if Brown had not been chancellor from 1997 and Prime Minister from 2007, multimillionaire Cameron would not have been tempted to claim for the cost of removing wisteria from the chimneys of his country pile.

He must think that we all came up the Thames on a bike if he imagines that this claim will convince anyone.

The electorate is still angry about the question of parliamentary expenses and it is convinced that the issue concerns more than just the three MPs and one peer facing trial.

The powers that be have ruled that MPs who gaily flipped designations of first and second residences to maximise public subsidies were not dishonest and simply played the system to their personal benefit.

Therein lies the basic problem.

The majority of MPs, from all sides of the House, have consistently agreed that the key to sound public finances is to hold down pay in the public sector, notwithstanding the already low levels of remuneration.

So as MPs would not appear as public hypocrites, Margaret Thatcher's Tory government devised the parliamentary expenses system to enable MPs to fill their boots while toeing the line on the scale of pay-rise percentages.

That is now clear to everyone, so Cameron's efforts to implicate one man as primarily responsible are utterly reprehensible.

Brown's political crimes are more serious than allowing MPs to pack their expenses.

His adoption of the Tory "choice" agenda in the NHS and his support for US overseas wars are far more serious than that.