Alex Salmond's confident leader's speech to party members yesterday in Glasgow stemmed from a sense that the Scottish National Party is on the crest of a wave that will sweep it into office on May 3. He may be right, though many a surfer hurtling majestically towards the shore finds himself unceremoniously upended long before reaching the beach.

Let us suppose that, despite serious doubts as to the viability of his plan for local income tax, Mr Salmond manages to stay on his feet and, come May 4, finds himself at the head of the largest party at Holyrood. After a period closeted with some of his former rivals in what used to be called "smoke-filled rooms", he will then emerge as Scotland's new First Minister, probably on the basis of a coalition with the Liberal Democrats, though at what political cost remains uncertain.

The biggest question everyone will be asking concerns the likely nature of his relationship with a Labour government led by Gordon Brown. Up until now, Scottish voters had been fed the idea that in such circumstances Mr Salmond would be looking for a constructive relationship with his fellow Scot. His deputy, Nicola Sturgeon, had given a similar impression. Then yesterday the script changed abruptly with the revelation that an SNP administration would be demanding within the first 100 days the start of talks on the transfer of responsibility for North Sea oil and gas. If Mr Salmond is looking for a fight, this is precisely where he will find it. What is the strategy here? Is it to stoke up an image of "Scotland v the Rest" in the hope of generating enough resentment to squeeze through a referendum on independence? This would be foolish and potentially counterproductive. Last week, Sir Tom Farmer, one of the SNP's main financial backers, suggested that the referendum could be put on hold until after the 2011 election, enabling the party to undergo a form of apprenticeship in office. Given that to date the party has not run anything bigger than Falkirk Council, this would appear to be eminently sensible. An SNP administration should have the humility to try its hand at day-to-day government in Scotland before embarking on a turf war with Westminster that could prove to be a dangerous distraction.

Meanwhile, the nationalists, who have relished their role in the cash-for-honours debacle, can expect to come under close scrutiny themselves in respect of the party's relationship with their latest major donor. Yesterday, the media focused on Brian Souter's self-funded £1m campaign to oppose the repeal of legislation that barred the promotion of homosexuality in schools. The SNP supported repeal and Mr Souter withdrew his support from the party as a result. Yesterday Ms Sturgeon insisted that the Stagecoach's tycoon £500,000 donation to the party's war chest came "with no strings attached". Not only should the SNP explicitly reaffirm its commitment to equal rights, but the party should also make it clear that Mr Souter - one of the main beneficiaries of bus deregulation - will have no special pleading in connection with public transport policy either.