Michael Brown: Every vitriolic remark makes Tory unity harder

With the holiday truce in the Tory war now over, there are still nearly four weeks left for Kenneth Clarke and Iain Duncan Smith, and their respective supporters, to knock each other to pieces. But the next few days will probably determine the ultimate winner. Although there is a frenetic month in prospect for the candidates, the bulk of the votes will be cast by the end of next week.

Ballot papers are dispatched on Monday and will probably be received on Wednesday. They will either go in the bin or be marked and returned immediately. Few will go behind the mantelpiece clock waiting for party members to deliberate after attending the regional hustings. Only a small proportion of party members, the activists, will even bother to attend such gatherings.

Eric Forth, the MP for Bromley and Chislehurst, tells me that out of his 1,000 or so constituency members, he has never met more than about 300. The rest, through inertia, simply pay an annual subscription. If they vote – which he doubts – they will do so quickly.

Any hopes that the campaign would be gentlemanly receded the moment hostilities resumed. Each has engaged the services of over-enthusiastic supporters who have resorted to the letters columns of the broadsheets to knock the living daylights out of the alternative.

The normally mild-mannered former party chairman, Michael Ancram, was unusually vitriolic in his dismissal of Mr Clarke – predicting all kinds of disaster for the party should he win. Not to be outdone, Mr Clarke engaged the services of another former chairman, Sir Jeremy Hanley, to predict a similar scenario if Mr Duncan Smith prevails.

Mr Ancram and Sir Jeremy have not made the healing of wounds any easier by their interventions. Mr Ancram, whose own appeal for unity was the primary basis of his own candidacy, undermines his case when he predicts that the election of Mr Clarke will result in "four years of division, internal wrangling, or even splitting". Should Mr Clarke win, how on earth does the Tory party have any hope of healing wounds with comments such as these?

Similarly, the prospects of unity are hardly helped when Sir Jeremy undermines Mr Duncan Smith by questioning whether "we should seriously consider rewarding a man with the leadership who showed more loyalty to a small rebellious group in Parliament rather than to his own party just when it needed it". On this basis, Sir Jeremy might have wondered how it was possible for Benjamin Disraeli, Winston Churchill or Harold Macmillan to have ended up leading the Tory party. In Churchill's case, there was also the burden of having been, previously, a member of the Liberal Party, but this did not prevent him becoming the hero of the modern Conservative Party.

The more senior figures in the party predict doom and disaster if their preferred candidate fails to get elected, the worse will be the prospects for the new leader healing the wounds inflicted from this bruising contest. Even at a local level, several MPs have taken to writing to their local party members reinforcing and entrenching these divisions by commending one candidate at the expense of vicious knocking copy against the other. My parents hold a joint membership of the Arundel and South Downs constituency and have just received a letter from their MP, Howard Flight – who supported Mr Portillo in the parliamentary ballot. Mr Flight says of Mr Clarke, "I do not, however, believe he can lead a united Conservative Party .... A party which would be so obviously divided could not win power."

So if Mr Clarke wins, how on earth will it be possible for Mr Flight, at subsequent meetings and election campaigns, to convey the message of the Conservative Party to the wider electorate? His political opponents, locally and nationally, will ensure such comments are thrown back at him and his leader for the rest of this Parliament.

Perhaps the one MP who has got it right is Humfrey Malins (Woking), who is "mildly fed up with senior Tory MPs, junior Tory MPs and former Tory MPs all writing in to announce, in blocks, their support for "X" in the Tory leadership campaign". He certainly spoke for my mother, who thinks that the MPs have had their say and that they should now keep out of this part of the process.

I have a suspicion that, unwittingly, the more MPs now try to influence the ballot, the more their local party members will do the opposite. Probably this will cancel out when the votes are counted but the price paid will be an entrenched division in the ranks among the parliamentary party that will be harder for the new leader to overcome.

It is all a far cry from the manner and style of previous contests where the candidates were careful to pay tribute to the strengths of their rivals. Even after the bruising removal of Margaret Thatcher in 1990, Douglas Hurd, Michael Heseltine and John Major went to considerable lengths to praise each other. One thing that Michael Portillo got right, during his failed leadership bid, was the need to "build up the other candidates – any one of which would be a good leader of the party".

The truth is that, while each may have deficiencies, it is absurd, and highly damaging, for Tory MPs to claim that one or other will be an electoral disaster for the party. The Tory party would do well to study recent Labour leadership campaigns – especially in 1994, between Tony Blair, John Prescott and Margaret Beckett – which, by comparison, were models of decorum. It would help if Mr Clarke and Mr Duncan Smith would each agree to become the other's deputy, and it is regrettable that Mr Clarke is going for leadership or bust. It would actually improve Mr Clarke's chances of winning if he could convey the impression that, whoever wins, he will play his considerable part in the Shadow Cabinet.

Mr Duncan Smith has hit upon the tactic of doing everything he can to avoid being labelled "the favourite". So far this is proving to be an effective weapon and, although I have no way of gauging opinion, my hunch is that he is now the favourite. But as I remarked when Mr Portillo appeared to be the early favourite, this is the most damaging epithet by which a Tory leadership contender can be so described. Based, however, on my two recent visits to address 150 party workers in the constituencies of Gillian Shephard and Andrew Mitchell – both Clarke supporters – by roughly two to one they favoured Duncan Smith.

Mr Clarke's task is to appeal to those he cannot easily reach, the silent majority of unknown, inactive supporters. But these are potentially his secret weapons. They know little of his rival but know Mr Clarke better through his wider profile upon the national stage. They are also less likely to be obsessed with the issue of Europe.

Most leadership battles end with clarion cries of congratulation to the winner by the loser, a willingness to set aside past differences to work alongside the victor, and elegant pledges of loyalty. The question I would be asking of both candidates is: "What will you do for the party and the battle to win the next general election if you should lose?"

mrbrown@pimlico.freeserve.co.uk