Inside Westminster: Slowly, the Whitehall machine has adapted to coalition. But it may well need to go further

This Government has been a good advert for sharing power

Nick Clegg, David Cameron, Ed Miliband and Angus Robinson enjoy their moment with Andy Murray, after the tennis player's Wimbledon win (Getty Images)

“You all seem to get along now, why can’t you always be like this?” Andy Murray told David Cameron, Nick Clegg and Ed Miliband at a reception for him in the Downing Street garden the day after he won Wimbledon this summer.

The venue was fitting: the Cameron-Clegg love-in held in the same garden after they formed their Coalition in 2010 was the high point of their partnership. Both men realised later it raised impossible expectations. Although the Conservatives and Liberal Democrats reached agreement on education and welfare reforms, the Prime Minister and his deputy learnt the hard way that their parties are very different.

The glue that has held the Coalition together is the need to tackle the deficit.

The other vital ingredient is the professional relationship between the two leaders. They are not the bosom pals they seemed as they laughed and joked in the Downing Street garden. The tension between them has at times been greater than they have let on. But they were united in their determination to keep the show on the road. Despite many predictions that the Coalition would end long before the 2015 election, it now looks like lasting until polling day.

A revealing insight into the Government was published this week by the journalist Matthew d’Ancona in his book In It Together. He concludes that the Coalition’s inner wiring is frayed but that, for all its faults, it works.

Although a lot of voters would agree with Andy Murray’s sentiment that politicians should work together better, d’Ancona reminds us that party self-interest – and sometimes political survival – comes first.

Mr Clegg lost his innocence when Mr Cameron authorised a ruthless campaign against him during the referendum on the voting system – after being warned his own position as Tory leader could be at risk if the Yes campaign won.

The boot was on the other foot when Mr Clegg blocked new parliamentary boundaries that would give the Conservatives a 20-seat bonus after Tory MPs scuppered his plans for a mainly elected House of Lords. “If I had not done it, I don’t think I would have survived another three months,” d’Ancona reports the Lib Dem leader as saying. Mr Clegg is said to have admitted he “wasn’t really leading” and declared he was not prepared “to be the last leader of the Lib Dems.”

Dark days. But like the Coalition itself, the Deputy Prime Minister has proved remarkably resilient. He had no option but to learn on the job. Mistakes were made early on. He tried to do too much and was swamped. He has a better team around him now. Slowly, the Whitehall machine has adapted to coalition – up to a point. It might need to go further.

As I travelled back from three weeks at the party conferences, I reflected that it is going to be very hard for either the Conservatives or Labour to win an overall majority in 2015.

True, Ed Miliband made the weather with his energy price freeze pledge and his deft handling of his row with the Daily Mail, which invaded the Tories’ conference airtime. But Labour had a reality check yesterday when a YouGov poll showed that 37 per cent of people believe Mr Cameron’s party is best able to fix the economy, while only 20 per cent opt for Mr Miliband’s. It put Labour just three points ahead of the Tories. So much for Labour’s hopes that it has “eliminated its negatives” on economic trust.

I doubt that, in the privacy of the polling booth, it will be trusted to tackle the “living standards crisis” until it convinces more people about its general economic competence.

However, that doesn’t mean Mr Cameron is set for a triumph in 2015. He pleaded at the Tory conference for the right to “finish the job”, which has a double meaning – it’s not safe to let Labour back and it is time to release the Tories from the shackles imposed by the Lib Dems.

Yet d’Ancona writes that the Prime Minister and his deputy have already discussed the prospect of a second coalition – a recognition of the mountain the Tories need to climb. Naturally, Downing Street and the Lib Dems have denied this claim, but it rings true.

Another hung parliament would not automatically lead to a second full-scale coalition. Some people in all three parties would be wary, and might prefer a looser “confidence and supply” arrangement in which the Lib Dems backed a minority Tory or Labour government in key Commons votes, without agreeing a joint programme or enjoying a permanent veto.

The Tory right would be wary of allowing the Lib Dem tail to wag the dog again. “We are not in coalition,” Margaret Thatcher is said to have remarked when told about the 2010 Cameron-Clegg deal.

Although Labour and Lib Dem policies have converged since then, Mr Miliband hints that he would not enter a coalition if Mr Clegg were still Lib Dem leader. In practice, it might be different. The Labour leader has never said never. Mr Miliband can’t be too nice about Mr Clegg now because it might give Lib Dem 2010 voters who have switched to Labour permission to return, annulling the main change in the polls since the last election.

Despite the doubts in all three parties about another full coalition, the one we have now has provided stability at a time when the country needed it. We would still need it after 2015. A big Commons majority is better than a government in hock to a handful of left-wing or right-wing backbenchers. Remember the chaos when John Major lost his majority? I don’t think Mr Cameron or Mr Miliband would fancy that.

The polls show we still prefer strong, single party government, suggesting that not much has changed since Disraeli famously said that England “does not love coalitions”. But this Government has been a good advert for them, and we may have to get used to them.