Furthermore, the Government's response to these events has been, at best, limited – and, at worst, flawed.

After the terror attacks, the Prime Minister and Home Secretary offered brief words of calm – Brown's finest hour. When swathes of Yorkshire and the South West were flooded, the response was ponderous.

Difficult questions about flood defence spending were raised and an entire region was only a few inches of water away from a catastrophic loss of power that would have triggered the biggest civilian evacuation since the Second World War.

The foot and mouth outbreak, it transpired, emanated from a Government-controlled laboratory. To compound matters, the premature lifting of movement restrictions – a move designed to indicate that the countryside was open for business – has now led to the detection of further cases.

And Northern Rock customers only stopped withdrawing their money during the recent credit crisis when the Chancellor guaranteed all deposits, setting a precedent that could one day have horrendous implications for the taxpayer.

It is also worth remembering the political legacy that the Prime Minister inherited. Once it had become clear Tony Blair would be leaving long before completing the full third term that he had promised to serve, Labour collectively began marking time.

Policies had little momentum as the imminent change in 10 Downing Street meant any new initiative, however worthwhile, was at risk of being dumped.

The only driving force was Mr Blair's desperate attempts to establish an alternative legacy to Iraq for historians to record. Any talk of a "smooth and orderly transition" provoked hoots of derision.

So, in June, Brown inherited a mess – and then spent the summer involved in less than spectacular crisis management.

And yet, if some opinion polls are to be believed, Labour is now even more popular than it was before the 1997 election when it won a landslide Parliamentary majority.

So significant has Mr Brown's impact been on the public mood that he and his followers are seriously considering calling an early poll next week to give the Prime Minister a mandate of his own, while potentially dealing the Conservatives another monumental setback.

The last three months have, therefore, been difficult for those who say voters are not seduced by image and personality as much as policy. Thus far, the Brown premiership has been strong on the former, and has involved very little of the latter.

Mr Brown has benefited principally from not being Tony Blair. The electorate had tired of the last Prime Minister whose authority had been steadily draining away since the Iraq war. His trademark style that lurched between lambasting the "forces of conservatism" – and a desire to be a friend to all – had lost its shine.

Voters were ready for a less polished approach – and Mr Brown has delivered that in spades.

But all Prime Ministers enjoy a "bounce" in the polls that a new face inevitably brings. Brown has prolonged that honeymoon period through shrewd political positioning.

His conference speech last week was viewed as an unashamed appeal to people on the centre-Right, but this was only his latest effort to capitalise on the conservative instincts of the British public.

Long before his appearance in Bournemouth, the Prime Minister had put distance between himself and Labour's previous positions on gambling, 24-hour licensing laws and drugs classification.

However, firm policies have been thin on the ground. His pledge to build more homes was inevitable from any Government faced with the current housing crisis. Scepticism over gambling has so far only produced a review of the supercasino idea and did not stop the new liberalised Gambling Act coming into force.

Round-the-clock drinking is also only under review – even though the Premier was part of the Cabinet that previously championed the relaxation of licensing laws.

Mr Brown's most substantive proposals were those relating to the constitution and the role of Parliament. Worthy and important subjects – but not what decides elections.

Last week, the Government even reverted to some old-style New Labour gimmickry with council tax rebates for some soldiers and deep cleans for hospitals, neither of which stood up to close scrutiny.

This tactic became even more stark this week when Mr Brown effectively hijacked the Tory conference to fly to Iraq to announce another "token" withdrawal of UK troops, even though he had previously promised to inform Parliament first of all such decisions. He was accused of shameless electioneering – and with considerable justification.

There lies the central dilemma for Mr Brown as he mulls over whether to call a November election, the first since 1950.

Over the last 100 days, he has restored confidence in the Government and increased Labour's popularity by virtue of some carefully chosen words and not being Tony Blair.

He will know that this prolonged honeymoon period, albeit one which he has successfully nurtured, cannot last much longer. Once Mr Brown starts taking difficult policy decisions, voters may come to the view that he remains New Labour through and through.

And while he has weathered, and even thrived on, a remarkable series of unforeseeable events, there is no guarantee that the next one will treat him quite as well.

After 100 days in office, Gordon Brown will be wondering whether this may be as good as it gets.