I think we might have found our election-winning subject: national insurance contributions seem to have become something of a sticking point for both parties in the battle for your votes.
It began last week, when the Tories managed to persuade more than 60 business leaders - including Marks & Spencer executive chairman, Stuart Rose, to sign a letter published by The Telegraph last week, arguing the 1% rise in NICs would stifle employment growth.
On GMTV yesterday morning, Brown defended his decision, saying the leaders have been 'deceived' by the Tories, whose savings are little more than smoke and mirrors - but Rose, never one to keep his opinions to himself - told the Today programme this morning 'to insult the collective intelligence of 60 plus chief executives is not helpful'.
While the fight between Brown and Cameron is likely to see its next round tomorrow, when Cameron has his turn arguing it out with John Humphrys, the battle to gain support from businesses has been going on much longer. Labour may have thought its straight-talking attitude would boost its reputation among businesses - but Rose's remarks show business feels rather let down by the party's approach.
"[Brown's] comments rather suggest that Labour's decided it doesn't need business support," wrote Management Today yesterday - and that may well be. But with economy at the centre of the election battle, it seems rather a shame to discount such a large portion of voters. Perhaps it's time for Labour to rethink its strategy - or lose out.