When the going gets tough, the tough get going. That, at least, was the impression Gordon Brown sought to convey to Scottish trade unionists yesterday when he took to the boards of the Eden Court Theatre in Inverness, though his real audience was sitting on the banks of the Thames, not the Ness. As with the theatre, the Prime Minister appeared to have had something of a makeover, striding about the stage without notes, Cameron-style. If a Scottish Labour Prime Minister cannot get a warm reception from Scottish trade unionists, he cannot get one anywhere. In the event, he was greeted by warm applause rather than a standing ovation. It was as much as he could have hoped for in the circumstances. After all, the business of government is about more than crowd-pleasing, though Alex Salmond and his Holyrood team may not have fully appreciated this yet.

When the going gets tough, the tough get going. That, at least, was the impression Gordon Brown sought to convey to Scottish trade unionists yesterday when he took to the boards of the Eden Court Theatre in Inverness, though his real audience was sitting on the banks of the Thames, not the Ness. As with the theatre, the Prime Minister appeared to have had something of a makeover, striding about the stage without notes, Cameron-style. If a Scottish Labour Prime Minister cannot get a warm reception from Scottish trade unionists, he cannot get one anywhere. In the event, he was greeted by warm applause rather than a standing ovation. It was as much as he could have hoped for in the circumstances. After all, the business of government is about more than crowd-pleasing, though Alex Salmond and his Holyrood team may not have fully appreciated this yet.

It was a clever speech in which Mr Brown conjured up one of Scotland's best-known exports - trade union leaders - to warn against the downside of separation from England. But though he took time to hail the Scottish trade union movement as a "rock for social justice", events elsewhere diverted him toward defending his administration on the two big issues of the day: the credit crunch and the abolition of the 10p tax rate. Twenty years ago, a £50bn government bail-out of the banks would have been greeted by this audience with howls of protest. Not so today, when trade union members, along with everyone else, need liquidity in the economy for first-time homebuyers, those coming to the end of fixed-rate mortgages and businesses needing to borrow before they can create jobs.

They were also well-placed to appreciate Mr Brown's other main argument: that, regardless of the row over the 10p rate, those living on low incomes are still better off under Labour, thanks to the minimum wage, tax credits and the rest. But those he really needed to convince were not 350 trade unionists but the 70 Labour MPs threatening to rebel on the issue next week, thereby handing a trump card to opposition parties on the eve of English and Welsh council elections. In case any of them were not listening, the Prime Minister flew back to London to address the parliamentary Labour Party last night, facing down the rebels and playing the loyalty card. But even the promise of jam tomorrow for the unknown number of net losers from the 10p change may not be enough. The government should admit its mistake, promise to counter it in the autumn pre-Budget report and plead for mercy. Any other course is politically suicidal. Few Labour MPs can relish a leadership contest, let alone a General Election.