Clarke denies personal tactics

Ken Clarke described his rival as a "complete unknown"

Tory leadership contender Ken Clarke has denied accusations he his stepping up the contest with personal attacks on his rival.

In an interview with the Times newspaper Mr Clarke described Iain Duncan Smith as a "complete unknown" who was more eurosceptic than William Hague.

He also suggested the shadow defence secretary might take the Conservatives on a disastrous "lurch to the right" if elected leader.

This is politics, it isn't personality - it was not meant as a personal attack.

Ken Clarke

A spokesman for Mr Duncan Smith said the Conservative Party was sick and tired of fellow Tories abusing each other.

But former chancellor Mr Clarke told BBC Radio 4's Today programme the comments were not personal.

"I haven't yet during this campaign attacked Iain Duncan Smith on anything or accused him of anything," he said.

He said the comments about his rival were in response to questions about the opposing camps' tactics for getting their message to party members around the country.

"In Iain Duncan Smith's case it is because he is not well known and has to get himself in front of members. In my case, I have to go round trying to explain what my views are other than on Europe."

Party loyalty

In Saturday's article, Mr Clarke suggests that his rival wants to take Britain out of the European Union and he casts doubt on his rival's loyalty to the party.

In a reference to Mr Duncan Smith's rebellion against John Major over the Maastricht Treaty, he said: "My history of loyalty to the party is impeccable.

"Personally, I have never taken part in any long, organised rebellions in cahoots with the Labour Party."

Iain Duncan Smith: Accused of being a never man on the euro

And he contrasts Mr Duncan Smith's position on Europe with that of William Hague.

"He [Mr Duncan Smith] is a never man on the single currency and wants to renegotiate the treaties.

"Iain's conclusion is that we were not eurosceptic enough at the last general election".

Mr Clarke told Today he thought he had explained Mr Duncan Smith's position on Europe accurately.

He also said he would be willing to appear alongside Tony Blair again on a pro-single currency platform, even if he won the Tory contest.

His previous appearance alongside the prime minister at the launch of the all-party Britain in Europe campaign stirred anger among eurosceptic Tories.

But Mr Clarke told Today it would be "sensible" for Conservative shadow ministers to appear on all-party platforms on opposing sides in a referendum on the euro.

'Unsubstantiated accusations'

The accusations have started flying ahead of ballot papers being sent out to the 300,000 party members on Monday.

The winner is due to be announced on 12 September.

Mr Duncan Smith refused to join the radio interview, but his spokesman said: "Iain Duncan Smith will continue to fight the campaign for the leadership of the Conservative Party on issues and policies that affect the membership and the general public of this country, not unsubstantiated accusations."

The campaigns continue on Saturday with Mr Clarke due to unveil his Green Belt policies in meetings with Tory members in Kent.

Mr Duncan Smith is due to address members of his Chingford and Woodford Green constituency association in Buckhurst Hill, Essex.