One of the accusations regularly thrown at politicians is that “they are all the same” and that “nothing will change” regardless of which party is in government.

It’s a cliché, no question – but one that has more than a smack of truth to it. When asked to name her greatest political achievement, Margaret Thatcher notoriously replied “Tony Blair and New Labour”, succinctly summing up the cross-party consensus on the merits of a small state and free markets that her long Premiership had instilled.

Similarly, the apparent ease with which the Conservative and Liberal Democrat parties were (initially) able to govern in coalition further signalled that party disagreements were cosmetic, not fundamental.

However, this year’s party conference season has seen party distinctions return with a vengeance. The coalition partners each sought to position themselves as the driving force behind the most obviously appealing elements of the government record – witness the fever with which Nick Clegg and David Cameron both tried to rubbish the other’s claim to have forced through the raise in the personal tax-allowance threshold. More interesting, though, was the level of fundamental differences revealed between Labour and the Conservatives.

The 2015 ballot is shaping up to be a “retail election”, with voters reluctantly plumping for the party that seems to offer the most attractive range of policy products. In this light, the new schism in British politics appears to be based not on competing ideologies but on contrasting views of “buyer preferences”.

Labour’s judgement appears to be that people will wander the political shopping aisles with an acute sense of persecution, on the lookout for policy propositions to help them cope when all is against them. Promises to join the fight against overcharging energy suppliers or land-hoarding developers speak directly to this sensibility.

Meanwhile, the Conservatives seem to have reached the opinion that the electorate has a fundamental sense of earned entitlement. Almost every speech given in Manchester this week was pitched unambiguously as “For Hardworking People” – a legend daubed on almost every wall of the conference centre. The big policy announcements were either about giving those that do the right thing their dues (eg, the married-couples tax break) or making sure that those that fail to don’t get a free ride (eg, the work-for-benefits scheme).

The days of rabid socialism v unrestrained marketisation are probably consigned to the dustbin of history, with the public broadly settled on the idea of an appropriate balance between an interventionist state and laissez-faire private sector. In its place we could be seeing the beginnings of a new binary divide between competing judgements on human nature. The assumptions each of the two main parties are making about the ways in which people make fundamental decisions are having a profound effect on the positions they are adopting. In light of this, the degree to which voters feel either put upon or deserving could be the deciding factor in 2015.