Tim Montgomerie: The centre ground is not broad enough for victory

At the last general election I found Michael Howard's manifesto unhealthily imbalanced. The former Tory leader offered Britain a thin programme and his campaign spent disproportionate time talking about immigration. At the time I repeatedly blogged in the futile hope that Mr Howard might start championing other causes - the very sort of environmental and socially responsible causes that David Cameron has now put at the heart of his modern, compassionate conservatism.

In his perfectly-pitched speech to Tory delegates yesterday, Mr Cameron talked about "a Britain that is more green". He promised "more family-friendly" policies and identified social justice and global poverty as foundation stones of his "brick-by-brick" rebuilding of the Tory house. I welcome these new emphases. They are essential for the Conservative Party to reconnect with the "Waitrose voters" who don't just shop ethically but vote ethically, too.

The trouble with these early stages of Project Cameron is that the whole programme is in danger of becoming almost as unbalanced as Project Howard. While Michael Howard was all about immigration, David Cameron is all environment. I exaggerate my case, of course, but many of David Cameron's advisers - egged on by too many commentators - argue that the Conservative Party has a choice between the new issues and the old. I think that's a false choice.

It is perfectly possible to combine strict immigration controls with a hard-headed, open-hearted commitment to fight global poverty. Lower taxation and social justice aren't incompatible if a tax-cutting agenda focuses on freeing Britain's poorest workers from the net of income tax. Few policies are as environmentally damaging as the EU's Common Fisheries Policy. David Cameron could please Eurosceptics and green voters if he pledged to retake control of Britain's waters.

Tony Blair attempted to occupy the whole political stage. Some Tory strategists only seem interested in the centre ground and they are leaving David Cameron's right flank dangerously exposed. They have slept through the wake-up call provided by the Bromley by-election and its warning that traditional Tory voters can always choose to stay at home.

In the failure to talk about crime, immigration and tax - alongside the gentler, greener messages - Team Cameron is not reaching the "Morrisons voter". Morrisons voters are largely Midlands and northern-based. Their wage packets are the main victims of uncontrolled immigration. They can least afford Gordon Brown's stealthy taxes. They are more vulnerable to crime and less able to opt-out of failing public services.

In America, Australia and Canada lower income families like Morrisons voters have become central members of the coalitions that have underpinned the recent electoral success of those countries' conservative parties. While many voters have moved leftwards as they have become richer, Bush, Howard and Harper have more than replaced them with appeals to cultural and socially conservative "strivers".

Until David Cameron offers a policy platform as broad as the coalition he needs for a majority, the Conservative Party's opinion poll lead will continue to be modest. The Independent/ConservativeHome.com survey of 1,500 grassroots Tory members shows that 65 per cent believe that the party should have a larger opinion poll lead given Labour's difficulties. An overwhelming majority of members are satisfied with David Cameron's leadership, but many are unhappy with his failure to focus on tax, crime, Europe and immigration.

The A-list is also a source of grassroots unhappiness. Just 6 per cent of members believe that the list of "priority candidates" represents the most talented individuals in the Conservative Party. More than half of members dislike its political correctness. They object to the way it has excluded some of the party's most talented and locally-rooted candidates.

The next election could be very close. Time is still on his side but David Cameron must recognise the narrowness of the current strategy. Adopting a policy platform that makes him more and more like other centre-ground politicians may help him with the voters floating between the main parties, but it will not appeal to the voters floating between voting and not voting at all.

The Conservative Party currently has a leader with the X-factor that is so important in today's politics. With a broader agenda I am still confident that David Cameron can be Britain's next prime minister.

The writer is the editor of ConservativeHome.com