Andrew Hawkins explains the factors that make this conference season unique, including how the next Labour leader can create a poll boost for the party

However you look at it, this year's party conference season will be a blockbuster. For the Tories, I suspect it will be a rather serious affair, taking place so near to the comprehensive spending review (CSR). Some will doubtless be using the conference to ask the sensible question about why the party didn't do better at the general election. They might also want to ask why the party is not enjoying a post-election honeymoon.

The Liberal Democrat conference in Liverpool should be upbeat and the best attended in the party's history. Old-timers will find the increased security arrangements a bore but they should regard these as one of the hallmarks of real power. It will also be rather perilous. Many will be unhappy at the party's partnership with the Tories, their poor poll performance since May providing proof that they're seen as having sold out.

The Labour conference will be dominated by the election of a new leader, the winner to be announced on the Saturday night. Conference will be extremely important as the new leader seeks to unite the party (and possibly the Miliband family) after the contest and start to build a new team to take on the coalition. Most urgent of all, in light of the haemorrhaging of support from its traditional voter base in May, will be to position Labour as the party in tune with the needs of poorer households. The incoming leader has a paltry 24 days to prepare for the CSR during which we can expect to be bombarded with the message that the Tories are cutting too much too fast.

Yet a honeymoon for the new Labour leader is not automatic as incoming party leaders have a mixed record. The chart below compares approximate poll averages for the leaders of the three main parties who took office since 1987. With the notable exception of Gordon Brown - who, ironically, enjoyed the largest honeymoon of anyone since 1987 in the immediate aftermath of taking over from Tony Blair - most have little impact on their party's short term poll ratings. The figures show that if an unpopular PM hands over the reins to an alternative leader, the honeymoon is much greater than doing it in opposition. The key question is why some register a boost while others pass unnoticed to the fore.

The only one whose election had a negative effect on their party's poll rating was poor old Sir Menzies Campbell, although Charles Kennedy and Iain Duncan Smith both had zero impact. Gordon Brown's success may be due to his massive media coverage and that he represented continuity with the popular aspects of Tony Blair's administration while being able to distance himself from the political toxin of the Iraq war. More remarkable still was that Brown's underlying ratings were largely negative: people thoughthe represented more of the same and that he would not be a good leader. Yet he still had a significant honeymoon.

David Cameron, Tony Blair and John Smith's election as leader all resulted in a noticeable boost to their respective parties. David Cameron's election as leader attracted colossal media attention, as did that of Tony Blair and indeed John Smith after Neil Kinnock's 1992 election upset.

Given the rarity of a new leader who depresses average vote share, it is reasonable to assume that Labour's next leader will enjoy a honeymoon, even if it is a modest one. That would still be enough to put the two main parties neck and neck and I expect some polls to show a Labour lead before this year is out.

So what do the parties need to do during this conference season? The public are remarkably accepting of the need for spending cuts. Even people in social group DE, the most dependent on public services, are split evenly over the scale of cuts proposed. Furthermore, two-thirds of voters believe the coalition government is better for the UKeconomy than a Labour one would be. In other words, it is pretty much only Labour voters who think that the party retains credibility on the economy.

However, storm clouds loom. The coalition is seen as more sympathetic to the interests of the rich and big business than to ordinary families. Also, when we ask people about specific public service cuts they are far, far less positive than they are to general questions about reducing the deficit.

All the party leaders, therefore, face an extremely difficult balancing act. The Lib Dems need to show that they still stand for something. The Conservatives have to avoid looking triumphalist given the hole that the country is in. And Labour has somehow to capitalise on its core voter concerns about spending cutsin a way that avoids reminding people why we're in this situation in the first place. It all makes for a conference season like no other.

Andrew Hawkins is executive chairman of ComRes

This article was first published in Total Politics magazine.