The Conservatives have put "presentation before principle", a former adviser to David Cameron has warned.
George Bridges' intervention has highlighted fundamental tensions at the heart of the Tory party - days after David Cameron appointed Lynton Crosby, the man behind the party's unsuccessful 2005 'are you thinking what we're thinking?' campaign.
Bridges recruited George Osborne to a researcher post in the Tory party before working in John Major's Downing Street and writing speeches for Michael Howard. He left the party after a spell working for Cameron.
He used an article for the Telegraph newspaper to warn that principles had been reduced to "attributes" as the Tories struggled to 'decontaminate the brand'.
"Just as Heinz may change the level of salt, the label or the price of a can of baked beans, political parties began to ditch or adopt policies to suit the public taste, day by day, week by week," Bridges wrote.
"The mindset of political strategy is now poisoning the well of politics.
"Those politicians who do have the guts to highlight unpalatable truths, and what they would do about them, are criticised.
"On Europe, politicians are told that voters don't care about it – so shut up.
"Meanwhile, politicians talk of taxing 'wealth' more because of what that would 'say' about their party, not whether it is the right or wrong thing to do."
Bridges' article is being viewed as an attack on the prime minister's approach to politics, at a time when the coalition is wrestling with questions on Europe and about how much to make the rich contribute to its deficit reduction strategy.
But it also undermines Cameron's main polling adviser Andrew Cooper, who faces speculation – in the wake of Crosby's appointment to the 2015 campaign – that he may be leaving No 10 soon.
As the Mail newspaper reported this morning, ComRes has been drawn into a row with the government over the use of its polling on gay marriage.
The Tories had previously rolled out polling data suggesting that the general public would support legislation putting same-sex marriages on a level legal status with heterosexual marriages.
Now a survey from ComRes published today suggests that the policy will lose the Tory party votes. Seven per cent say they are more likely to vote for the Conservatives as a result, but 18% say they are less likely.
Sixty-five per cent said the gay marriage plans, backed by the Liberal Democrats, are more to do with making the Tories look 'trendy and modern'.