Labour’s Annual Conference this month could hardly be taking place against a less auspicious backdrop: a faltering economy, the party 20 plus points adrift in the opinion polls, and continued unease about the government and prime minister’s supposed lack of direction and inability to communicate with the voters.

Alistair Darling’s uncharacteristically blunt assessment of the situation – the voters are ‘pissed off’ with the government – seemed to capture perfectly the public mood. It appears, however, that Jack Straw – alongside the chancellor and Gordon Brown the only minister to have sat in the cabinet continuously throughout Labour’s 11 years in office – does not wish to share a similarly salty turn of phrase with the nation: ‘We all use our own language but it’s perfectly obvious that in a time of economic difficulty, particularly if you’ve been as powerful as we have, people are likely to point at the government [and] we have to take that on the chin.’

But that doesn’t mean the justice secretary doesn’t have an equally forthright message for the government and party about the current political situation: get a grip. Straw, who has sat on Labour’s frontbench since 1980 and is now the only member of the cabinet to have served in parliament throughout the 18 years of Tory rule, appears irritated by the lack of perspective he detects in some of those criticising the government’s performance: ‘I see people now fretting, it’s hard to describe – this is nothing; we’re in government and we’ve got the major part of two years before a general election. And the election is ours to win,’ he argues.

As a veteran of 37 conferences, Straw believes ‘Labour has faced much worse circumstances objectively.’ Look at the setting for Labour’s 1968 annual conference, he suggests: devaluation the previous winter, disastrous local election results that spring, massive cuts in public spending and a huge internal row over the In Place of Strife union reforms. And Straw recalls his time as a special adviser in the 1974-79 government: ‘The 1976 conference at the time of the IMF cuts was horrible, probably about the worst conference we’ve ever had when fisticuffs broke out at the Tribune rally between Ian Mikardo and Jack Jones and Denis Healey turned back at the airport to speak at the conference and was then given three minutes [in which to do so].’

Those kind of fights – both the physical and ideological – are now long behind Labour, believes the justice secretary: ‘Crucially, what we have to do is be more united and that’s strangely not that difficult because there aren’t these visceral divisions that there were in the early 1980s. It wasn’t a huge amount of fun [then] because the issue for the Labour party wasn’t whether it was going to form a government but whether it was going to survive.’

The differences of opinion within the party today – over levels of tax, the delivery of public services, and the best way to rebuild the coalition that brought Labour to power in 1997 – are simply not of the same scale, Straw argues. ‘In the early 1950s and early 1970s, conference was replete with division. One of the things that’s frustrating at the moment is that there is none of the ideological division that there was before. The basic divide in politics in those days went through the Labour party: between those who essentially still believed in the Marxist-Leninist approach to the management of the economy and society and those who didn’t [and who] took a Croslandite view.’

Nonetheless, Straw is concerned that, despite these facts, Labour’s current infighting could come at a high cost: ‘There is a much greater level of unity today [in the party]. But what I also know is that it is disunity, and the manifestations of disunity, which detach you from the electorate and make it very difficult to get your message through.’

The government’s inability to get its message across – we have ‘patently failed to communicate what we are for and what we are about’ – was, of course, one of Darling’s other insights in his Guardian interview. Does Straw share it? The justice secretary accepts that, ‘there’s a danger if you’ve been in government for some time of leaving unsaid what you’re for.’ And he believes that, ‘one of our key challenges’ is not simply explaining why the current economic difficulties have arisen ‘so fast and to a depth no-one anticipated’, but also ‘getting across that … you never need a government of the left more than at times of difficulty … to try and counter these insecurities and unfairnesses and the inequalities they produce.’

References to ‘fairness’, the widely predicted wrapping that will package this autumn’s measures by Brown to help those struggling in the face of the economic standstill, pepper Straw’s comments. But the justice secretary is quick to stress that ‘we have to get across why policies of fairness and greater equality are important to everybody, to the “haves” and “have-nots”‘. Which is why Straw – the first senior figure in the party to call for the abolition of the old Clause IV in the wake of Labour’s defeat in 1992 – is dismissive of those who suggest that ‘New Labour is dead’ or should be killed off. ‘They’re not thinking through what is meant by that. Had we not changed Clause IV and ensured that our objectives were framed in the light of the circumstances in the late 20th century and early 21st century, rather than the early 20th century, we would not have got a mandate for three terms [and] probably not even for one.’

Looking back, the justice secretary goes on, ‘I’m in no doubt that what we did between 1993 and 1995 was essential for the health of the left and our ability to reach out to voters. What New Labour was able to do was produce a coalition of the “haves” and “have-nots” and, as I can witness, if you don’t have that coalition, if you don’t have that power, then you’re in a situation we were in for 18 years where you can’t do anything for the people who need you the most. I’m not going back to that.’

However, hasn’t Labour badly fumbled the gauntlet thrown down by Tony Blair in his final conference speech two years ago when he said of the Tories: ‘if we can’t take this lot apart in the next few years we shouldn’t be in the business of politics at all’? Straw believes that ‘the party has taken time to catch up with [the fact that] the Tory party has got a lot more serious about opposition and wanting power.’ He goes on: ‘I’m clear [that] we have to improve the way in which we take the Conservatives apart.’

Could Straw be the man to do it? With speculation about the leadership continuing to rumble on, the justice secretary is frequently tipped as the kind of ‘safe pair of hands’ the party might turn to if the premiership fell vacant. Straw has survived for over two decades in frontline politics by knowing never to flirt publicly with such notions. He acknowledges his longevity – ‘I’ve been around for a long time, but I don’t feel my chronological age, I see it as a bit of a nuisance that these decades have passed’ – but to what does he ascribe it? ‘Luck, porridge and the gym,’ Straw jokes. ‘I am obsessive about the gym because I’ve always reckoned inspiration is 90 per cent perspiration. The gym is not optional, particularly when you’re under pressure.’ He goes on, ‘I’ve got a lot of energy, I’m sociable, and fascinated by intellectual challenges.’

But then, perhaps rather more revealingly, he continues: ‘I think it’s also about being single-minded, not obsessive, but single-minded about my politics.’ That trait has taken him far. Would anyone bet against it taking him still further?