After John Smith died in May of 1994, certain Blairites began to put it about that the lost leader, fine man as he was, could not have won a General Election.

As a matter of record, Mr Smith's Labour Party had a 15% opinion poll lead at the time of his passing.

Acolytes of the successor did have a point, of sorts. After Tony Blair was elected leader in July, Labour's lead in the polls went up to 21%. It rarely fell below double figures thereafter. In March of 1997, just before the General Election, the party had an 18% advantage, according to ICM. On the eve of polling, the figure was 13%. The actual winning margin was 12.5%.

Westminster's coalition politics has caused a lot of people to forget what success and failure used to look like in these British contests. A few can summon the cliche of Michael Foot, his manifesto derided as "the longest suicide note in history", leading Labour in 1983 to its worst defeat in half a century. Forgotten is the fact that in December of 1981 the lowest approval ratings ever recorded for a Prime Minister were attributed to Margaret Thatcher.

Mr Foot, mocked on all sides, was obliged to contend with the self-seeking Gang of Four and Social Democratic deserters. In 1997, Mr Blair had to pay attention to a still robust Liberal Democrat Party capturing almost 17% of the General Election vote. So what's the problem with Ed Miliband?

The most recent YouGov British survey (January 31) has the Conservatives on 33%, Labour on 42%, LibDems on 10% and Ukip on 7%. Scottish figures are wildly different, of course, but set those aside. The UK poll average for the three main Westminster parties is as follows: Con 32%; Lab 40%; LD 10%. For Mr Miliband, this is the wrong side of sensational.

Two years ago, in January of 2011, Labour was polling at 44%. Since then it has struggled to achieve or hold a double-digit lead, even with the LibDems toiling. Worse, in YouGov's tracking of the personal standing of the three party leaders, Mr Miliband does worse than David Cameron. This is, or ought to be, astonishing.

As things stand, and if nothing goes wrong, Labour will still win the next General Election in reasonable comfort, particularly with the threat of boundary changes averted. But only a deeply optimistic supporter is liable to feel inspired. With Mr Cameron talking of all the things he plans to do after the next election – on Europe, on defence, on welfare – the landscape created by coalition politics is strange. A lot can happen. Scotland's independence referendum, with unknowable effects on the Westminster game, must happen.

For now, each of those three main parties is in possession of a young, energetic and deeply unpopular leader. When polled, 55% reckon that Mr Cameron is doing a bad job. Nick Clegg has an approval rating of only 20% – big surprise – with 71% dissenting. Mr Miliband's Labour leads the pack, but only 32% of those asked think he is doing a good job. With 58% failing to approve, he trails his own party.

Last weekend, a London Sunday newspaper ran a curious tale involving Adam Afriyie, a hitherto unknown Tory backbencher. Mr Afriyie happens to be a millionaire, he happens to be black, and he happens to be the least likely candidate imaginable for the Tory leadership. That, though, was the proposition. The Prime Minister who had just been cheered by Tory MPs for his strange speech on Europe was facing, in the parlance, a stalking horse.

It came to nothing, of course. The interesting question was why the idea had been fed to a Tory tabloid newspaper in the first place. This week, the gossip returned, with another tale from the Westminster bubble claiming that Mr Cameron has been given warning of a confidence vote by next summer if he does not buck up and improve Conservative poll ratings.

It seems he is no more popular in his party than he is the country. It is clear, moreover, that he was accepted as leader for the sole purpose of winning the 2010 General Election. This, lest we forget, he failed to do. Mr Cameron's Tories picked up two million more votes than Labour, but only 48 more seats. Hence the deal – long anticipated, it is now clear – with Mr Clegg. Mr Cameron is detested by many Tories for his social liberalism, but despised for having to cut a deal with Liberals.

Mr Clegg is meanwhile the subject of leadership rumours on a monthly basis, generally involving the likes of Vince Cable or Ed Davey. The opinion polls speak for themselves. If they remain unchanged, all the gains achieved by Charles Kennedy in 2005 – and then some – will be forfeited in 2015. Mr Clegg, after all, was another who failed to prosper in 2010, dropping five seats.

With opposition such as this, Mr Miliband's lead ought to be unassailable. But with the LibDems in deep decline, Ukip leeching Tory votes and 79% of voters saying their most important concern is the economy (stupid) an 8% to 9% opinion poll lead is pitiful. Tory successes in blaming Labour's record in office for austerity – nothing to do with the trillion pounds diverted to banks – do not explain everything.

Mr Miliband is one of a trio of weak Westminster leaders. He differs from the Coalition pair only in that he faces no talk of a leadership challenge, and that's thanks only to his party's modest lead in the polls. The striking fact is that a country in severe economic and social difficulties has produced, in Westminster, not a single dominant voice, no clear set of arguments for or against a course of action. British politics, you might conclude, has got the leaders it deserves.

The Coalition's stewardship of the economy has been a rank failure. How many recessions are required for proof? Mr Cameron and Mr Clegg respond by insisting, in a comical echo of past calamities, that there is no alternative.

They press on, tempting voters with receding horizons: 2014, 2015, 2016 and beyond. Questioned, they offer no guarantee that anything will have improved by those dates. Sometimes they admit that, for the least well-off, things will get worse.

Mr Miliband's grand and only alternative plan is to urge a slower pace. For the sake of "fiscal responsibility", he too would make cuts, deep cuts, but somehow they would be less painful cuts. He will make no other promises. Which is to say, he declines to offer real hope to a population caught in the deepest depression this country has seen. Snapshot opinion polls record the response. Labour leads only because Mr Miliband is given the benefit of slight doubt. Surely he couldn't do worse?

These three leaders, these men being led, are the pure products of Westminster. It's not so much that they "lack experience" of the wider world, though they do, as that they cannot think beyond the bubble. Mr Clegg was an MEP at the age of 32; Mr Cameron joined the Conservative Research Department after graduating; Mr Miliband was a special adviser within a year of leaving university.

Now these individuals congregate around the same few assumptions and ideas. Now each claims the honour of leading his party nowhere in particular. You can only wonder when the parties, and Westminster generally, will begin to notice a pattern.