Gordon Brown was flying around like a kernel of popcorn in a heated pan from one political disaster to the next. Snap! Crackle! Pop! The Labour Party was bursting as it saw its day of reckoning coming. David Cameron's plan was simple enough, appear calm in a crisis, look statesmanlike, offer the hand of cooperation, and don't kick a man when he's down. It's not British.

Well, has he blown it? Has David Cameron achieved what, when I was at the Labour conference three weeks ago seemed nigh impossible, setting up Gordon Brown to win Labour a fourth term? Has Cameron, at a time of testing, shown that his judgement is apt to be naïve, and possibly even cowardly?

There is no doubt that Gordon Brown is enjoying himself at the moment. He is centre stage as Western governments try to salvage the global financial meltdown that they have all been party to. The latest Nobel laureate economist is lauding him while the American and European media are tripping over their epithets as they rush to proclaim him an economic saviour.

I have no problem with Cameron wanting to look supportive in a time of crisis, but he seems to have nothing to say at all while Brown washes the blood off his hands from this capital homicide that he is as guilty of as any banker. While offering to help pass urgent legislation Cameron should be shouting out the charge sheet that Gordon Brown must face once the crime scene returns to normal.

It was Gordon Brown that rigged the measure of inflation so that it no longer included the cost of mortgages, thus ensuring that the Bank of England, given the task of suppressing inflation, has been setting the wrong interest rate since almost day one. This contributed to our culture of easy money.

It was Gordon Brown that after only two years dumped the straight laced Prudence that Ken Clarke had introduced him to and chose to paint the town red with that big spending floozy Profligacy. Brown's binge spending went from £350bn in 2001 to £530bn today – £100bn more than inflation – supporting a consumer-led boom and easy public money.

To try and pay for this it was Gordon Brown that shoved our taxes up so much that the economy has now slowed down, Treasury receipts have collapsed and government borrowing has consequently soared to cover Gordon Brown's bar bills.

It is Gordon Brown that has behaved Mugabe-like; debauching our currency by printing extra money that Britain has not earned – feeding inflation into our economy. With real prices of consumer goods from Asia deflating prices the inflation had to go somewhere – and it did, into property. It was Gordon Brown and his Chancellor that dithered over Northern Rock when its demise was being talked of for months before – and then repeated the with Bradford & Bingley.

And it was Gordon Brown that established and presided over the current regulatory system that has failed so abjectly.

It didn't need to be that way, Gordon Brown had started well, he stuck rigidly to tight Tory spending plans, he made the Bank of England independent, why, there was even a tax cut.

By offering Gordon Brown his hand of co-operation Cameron has conceded the floor and appears to be accepting there is a failure of capitalism that only socialist measures can repair. Why is he not pointing out that not all banks have had to go cap in hand to the government, that just as there are some failing banks there are some failing governments and Brown's is one of them?

It was Gordon Brown who said "no return to boom or bust" and other wonderful one-liners such as "I will not allow house prices to get out of control". Nobody's laughing at them now. David Cameron should be turning to Maurice Saatchi and asking him to cover the country's hoardings in 48-sheet posters of Brown's guilty face next to those words.

Cameron needs to go on the assault, he can still offer the hand of cooperation but in his other hand must be an almighty large club – formed from Brown's economic conceits that he peddled, with one word carved across it – hubris.

Cameron should be raising the question that if it was right for Fred Goodwin and Andy Naylor then why are the Prime Minister and his Chancellor still in a job? And if he thinks it unseemly to do it in the Commons then he should get himself on the first train to Glenrothes, stopping off at stations on the way, telling the public how it is.

This isn't a just a banking crisis, it's also a political crisis – it's not just some banks that are failing but Her Majesty's Loyal Opposition too. If the blame is not pinned on those politically responsible then the myth will stick that it was all those bankers fault, especially the ones on Wall Street. Brown will even pass the buck for the looming recession. Without a new Cameron plan Gordon Brown might just win the Glenrothes by-election and is certainly able to win the General election.

It is times like these that test a prime minister, but they also test the leader of the opposition – and at the moment I suggest he has been found wanting. It's not too late to change his tactics, but if he leaves it for a moment longer he will find out that such is the pace of global events even a day can be a long, long time in politics.