Cameron praises wife's good sense

The Conservative Party leader will praise his wife's ability to keep his feet on the ground when he gives an insight into his family life on television.

Cameron's charm offensive continues as he tries to reinvigorate his election chances as more polls suggested he is unlikely to win an outright majority. Research by YouGov found the Tories' lead had narrowed from five points to four over the past week.

They were down one percentage point on 37 per cent, while Labour and the Liberal Democrats were unchanged on 33 and 17 per cent respectively.

If repeated at a general election, the results would leave Labour as the largest party with 302 seats, against 277 for the Tories. No party would have an overall majority.

In another poll, ICM found the Tories had dipped by two points over the past month – to 38 per cent, compared with 31 per cent for Labour.

The poll suggests Cameron would be in control of the largest party, but 30 seats short of an overall majority.

The polls were published on the eve of Cameron's interview with Sir Trevor MacDonald, in which the Tory leader pays tribute to his wife. "She has good judgment and great common sense and is wonderfully good at keeping you pinned to the ground," Cameron says.

Her ability to bring him down to earth was in evidence when he arrived late for a holiday in Devon because he had been meeting Barack Obama.

The Tory leader was talking about meeting the new US president when his wife said: "You know, I'm not really interested." According to Cameron, his wife then said, referring to their children: "That one needs his nappy changed. That one needs to get dressed. Now will you get on with it?"

Cameron's tribute is the latest move in the plan to raise his wife's profile during the general election campaign. Her decision to become more involved in politics follows the positive publicity Sarah Brown has generated for the Prime Minister.

Samantha Cameron will appear with her husband on Trevor MacDonald Meets David Cameron on ITV1.

Like Brown, Cameron will describe the trauma of losing a child, reflecting on the life of his disabled son Ivan, who died last year aged six. The tragedy made him re-evaluate whether he still wanted to be in politics. "After Ivan died, I did think, 'Is this what I want to do, is this life?'"

While Cameron admits to having a temper, he attempts to contrast his behaviour with Brown's volatility. "I don't lose my temper as in flying rage with bits of furniture going round the room, but I get excited. I certainly have temper."

He describes his father Ian as his hero. "He's an amazingly brave man because he was born with no heels… back in the 1930s with quite a disability."

Trevor MacDonald Meets David Cameron, tonight, 10.15pm, ITV1.