It is nothing short of remarkable that Britain formed its first coalition government since the Second World War in the space of just five days. Our Continental cousins often take weeks, if not months, to construct viable governing alliances. Just ask the Belgians, who had their own general election back in June; few in Brussels expect a new coalition government to emerge any earlier than October.

“England does not love coalitions," proclaimed Benjamin Disraeli in 1852. But a century and a half later, his political heir David Cameron seems intent on proving him wrong. The Prime Minister described his alliance with the Liberal Democrats as a "historic and seismic shift" in the British political landscape, as he stood shoulder to shoulder with Nick Clegg at their joint press conference in the Downing Street rose garden on 12 May.

In the days that followed, left-wing critics of the coalition first had fun trawling through pre-election quotes from Tories savaging Lib Dems and Lib Dems savaging Tories, and then expressed dismay and outrage as the Lib Dems surrendered one manifesto pledge after another. "I think you should grow up," said one irate Lib Dem MP to me during a live discussion on the radio on 14 May, after I'd challenged him on his party's decision to drop its opposition to Trident and tuition fees.

Transparent trap

In hindsight, perhaps he was right. Coalitions are based on compromise, on give and take; two parties sacrificing policies and promises in order to form a coherent and credible governing alliance. But, as ever, we British tend to do things with a twist. Whereas on the Continent, two parties tend to come together to agree on common policies while jettisoning the divisive ones, the Con-Lib alliance has turned the entire concept of a coalition on its head. Cameron and Clegg have used the cover of their "historic" coalition to push through new, drastic and divisive policies that did not feature in either of their parties' manifestos nor, in some cases, the coalition agreement documents.

There remain rumblings on the back benches and - in comments that will alarm the coalition's leadership - the keeper of the Lib Dems' social-democratic flame, Simon Hughes, the party's new deputy leader, tells me: "There is a danger. I think we need to be careful that we don't start adding and taking away [from the coalition agreement] without a public and transparent process."

But transparency has been in short supply. During the election, both parties failed to alert voters to the rise in VAT that they promptly introduced in the coalition's first "emergency" Budget. Neither party campaigned on a platform to grant anonymity to rape defendants, which is now government policy. "Well, it was Lib Dem party policy," says one defensive Lib Dem source.

But as Richard Grayson, vice-chair of the party's federal policy committee and a critic of the coalition, points out: "We've got shelves and shelves of policies, including a ban on giving goldfish as prizes in fairs, but they didn't all make it into the manifesto either, did they?"

Then there is health and education. The Tory and Liberal Democrat general election manifestos ran to around 50,000 words combined; the two coalition agreement documents amounted to another 17,000 words. The election campaign featured four and a half hours of live, televised debate between the three party leaders. Yet in none of these documents or debates was any reference made to the policies on NHS reform or higher education funding that Cameron and Clegg have since introduced in office.

On 12 July, the Health Secretary, Andrew Lansley, announced the biggest shake-up of the National Health Service in England since its creation in 1948, in a move gleefully described by the boss of one private health company as "the denationalisation of health-care services". Lansley's sweeping plans for the NHS include using markets - not targets - to improve performance and handing £80bn of the health budget to GPs to manage. The coalition agreement specifically pledged to "stop the top-down reorganisations of the NHS". What changed in the space of eight weeks? Where, now, is the mandate for such a change? "The NHS plan came from inside government and didn't involve either of the parliamentary parties," says one Lib Dem backbencher.

On 15 July, the Business Secretary, Vince Cable, called for a "radical rethink" of how universities are funded and revealed that he planned to ask the review of university fees and funding being made by the former BP boss Lord Browne to consider "the feasibility of variable graduate contributions". Richard Grayson, who was involved in the Lib Dems' election manifesto, says: "I never once saw Vince argue for a graduate tax before the election, either in private or public." Even before Cable's announcement, a senior Lib Dem source had warned me that the issue of higher-education funding has the potential to split the coalition - or, at least, divide the party's ministers from its backbenchers.

National assurance

Hughes tells me he has an "undertaking" from his Lib Dem colleagues in the cabinet that the Browne review will be allowed to publish its findings before the coalition gives its considered response. "I don't believe the government has already made up its mind on a graduate tax," he says. "And I hope we will not now see any deviation from the coalition programme without agreement from both sides."

The warning from the Lib Dem deputy leader is clear but supporters of the coalition seem relaxed. "I don't think people will be bothered about whether policies were put to them in a manifesto or not; the issue is whether they like them or not," says a Lib Dem strategist. Indeed, the government is still benefiting from its honeymoon: approval ratings are high, the sun is shining, Cameron and Clegg are still smiling. "This is, after all, the new politics," says a senior Tory strategist. "The coalition was formed in the national interest and we are governing in the national interest."
What defines the "national interest" is debatable and such moves contribute to the ongoing distrust of politicians by the voters - and could wreck relations between ministers and backbenchers in both parties. They could also undermine the legitimacy of future coalitions, especially if they are seen by the public as a convenient excuse for undemocratic, back-room deals and - worse - untested policies.