Timely advice

That, of course, is not the only thing that the two former premiers have in common. Both were natural winners, each gaining three consecutive General Election victories through their instinctive understanding of how to extend their respective party’s support beyond what were thought to be its natural boundaries.

The way in which Labour has happily retreated back to those boundaries, therefore, is quite remarkable. Indeed, as Mr Blair suggested yesterday in his stark warning to the party, the battle lines have now returned to those of the 1980s – as if Mrs Thatcher was still in power and New Labour had never existed.

But however unwelcome Mr Blair’s intervention, Labour leader Ed Miliband must know that he cannot afford to disregard the advice of his most successful predecessor.

From within the comfort blanket of a handy poll lead, Labour seems happy merely to paint the Conservatives as the party of austerity, instituting cruel welfare cuts without regard for the disadvantaged.

But what the Labour leader does not seem to realise is how vulnerable that poll lead is when other surveys show that the voters understand the need for austerity, welcome attempts to control the welfare budget and see David Cameron as a far more convincing Prime Minister than they do Mr Miliband.

As Mr Blair says, Labour has to do much more than merely criticise Government policies, it has to provide its own answers to the questions that confront the country. And perhaps the most important question of all for Mr Miliband is what a party whose very raison d’être is public spending can offer the voter when there is no money left to spend.