Subliminal advertising flashes a word on to a screen so briefly that you do not know you have seen it, but it enters your mind nonetheless. When David Cameron rose yesterday to make his first speech as leader to a Conservative party gathering, he did not rely on such subtleties. He stood in front of the word “Change” written in block letters that dwarfed him.

In almost his first sentence, he remarked that every day in his morning meetings he has “David Davis on my right and William Hague on my left”. Apparently, the irony was lost on Cameron. He sits flanked by the man who contested last year’s leadership election as the “no change” candidate, and by the former leader who fought the 2001 election on narrow nationalist slogans such as “Save the pound” and “Come with me and I will give you back your country”.

If the contradiction is unclear to Cameron, it is apparent to the public. As the Tories journeyed to their mini-conference in Manchester, opinion polls showed that while electors recognise that the new leader is a fresh face, they are unconvinced that change has occurred any deeper in the party.

At the moment of his triumphant election as leader Cameron made a choice. He passed up the opportunity to signal a complete break with the past, which he could have done by giving the top jobs to a new generation of Tory politicians. He blinked at the prospect of making explicit the division that exists in his party between the modernisers and those who have resisted change despite three crushing general election defeats. Now he is paying the price.

It is not just that Cameron has been magnanimous to Davis and Hague, who might conceivably have a political future. He has pulled in Iain Duncan Smith, Kenneth Clarke and John Gummer, giving each of them a role in policy-making. Lord Heseltine has returned to the Today programme thanks to being appointed by Cameron to study inner cities, and the former big beast was given a starring role on the platform in Manchester.

Voters find it hard to believe that the party is undergoing a revolution when they see it represented by the faces that lost those three elections. They hear “change” but the subliminal images tell them something different.

This matters particularly because Cameron lacks other opportunities to demonstrate that the party has moved forward. Tony Blair offered proof that Labour had become something new when the party repealed Clause 4 of its constitution, which had committed it to nationalisation. The Tories have no equivalent policy shibboleth that can be jettisoned.

Their new leader has set about changing the way in which parliamentary candidates are selected, in the hope that the party will in future be represented at the polls by personalities who properly reflect their community and their country. But even if the new process is a perfect success, those candidates will not be in evidence until the next election and will not reach the upper echelons of the party for some time after that.

Cameron faces a quietly sceptical response from many in his party. Noisy opposition would suit him better. If he could be seen to battle the forces of reaction and win, that at least would provide proof of progress. But the party’s right seems to have cottoned on to that. After making a helpful assault on Cameron during his first weeks as leader, Lord Tebbit and others of like mind have gone quiet. They are not going to help Cameron to create an illusion of painful and irreversible change, nor are they going to attract blame for undermining the duly elected leader.

In his speech in Manchester, Cameron skilfully delivered counter-intuitive messages. He knows that every day he must say what people do not expect a Tory to say on subjects that they would not expect him to choose. He has to demolish the pigeonhole in which his party has been imprisoned for many years. Yesterday he spoke about helping those who care for disabled relatives, and people struggling to get on to the housing ladder. He declared that the party should not dictate social norms but rather help people to make their own choices on whether to use childcare in order to go out to work. He called for a green revolution.

What he did not say was as important. He avoided tax, immigration and Europe.

His careful choice of subjects makes still more surprising two mistakes that he has made. Early on, he promised that marriage would be recognised within the tax system. The pledge unhelpfully suggests a harking back to the old Tory party. It can offend single parents, people who live together without marrying, gay people and single people, for whom life is particularly expensive.

The other error is to persist with disengaging the Conservatives from the European People’s party (EPP) in the European parliament. It is true that this transnational grouping with which the Conservatives are allied has views on European integration that the Tories do not share. But a dog that has been allowed to sleep during the leaderships of Margaret Thatcher, Hague, Duncan Smith and Michael Howard could surely be left to slumber some more.

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