Common sense has prevailed and now our first coalition government since 1945 has to work together for the good of the nation. Here, John Hipwood looks at the task ahead.

David Cameron had been forced to wait for five days, but finally he stood in Downing Street last night to talk soberly about the “full coalition” he had formed with Nick Clegg. Common sense had prevailed.

The gates had been opened because 26 hours and 20 minutes after making his ‘I’m trying to hang on’ statement in Downing Street, Gordon Brown stood on the same spot yesterday evening and conceded that the game was up.

So the man who won last Thursday’s general election but without the necessary points on the scoreboard was finally asked by the Queen to form a government.

Dignified at the end, Mr Brown, his stoical wife, Sarah, by his side, and with the words “thank you, and goodbye” ended the era of New Labour dreamt up by Tony Blair and Mr Brown.

The ConLib (name suggestions by email, please) era was about to begin with the unlikely duo of 43-year-olds, David Cameron and Nick Clegg in power and leading us into the unknown.

Less than an hour after the outgoing prime minister had travelled to Buckingham Palace to tender his resignation, Mr Cameron’s Jaguar was driven into the Palace quadrangle to accept the Queen’s invitation to form a government.

The United Kingdom’s new Prime Minister, on arriving in Downing Street was gracious towards the outgoing Labour administration, paying tribute to Mr Brown’s dedication to public service, and commenting that Britain was now “more open at home and compassionate abroad”.

In a statement which contained not an ounce of triumphalism, Mr Cameron warned of the “hard and difficult work” ahead, and pledged that the coalition aimed to provide “strong, stable and decisive government”.

Constitutionally, Mr Brown was right to remain at No 10 while Messrs Cameron and Clegg tried to agree a deal. But his desperate last-ditch intervention late on Monday afternoon to try to block an agreement demeaned himself and his office.

The voices of reason old hands John Reid and David Blunkett argued strongly that Labour should accept defeat, re-group and begin to rebuild.

Young gun Andy Burnham, one of the most partisan cabinet ministers, was of the same opinion.

Interesting and informative to hear the Lib Dem negotiators report that their Labour counterparts Mr Brown’s representatives weren’t serious and that cabinet ministers were more interested in being in opposition than entering into a progressive coalition.

Nick Clegg, the man in the middle of the political sandwich, will have a vital role to play over the coming months, as Deputy Prime Minister.

His reputation was damaged by the sudden apparent lurch on Monday towards Mr Brown, having signalled time and again that this was a man he could not work with.

Many Liberal Democrats hate the Tories and this left their leader with a difficult task to bring them on board. That’s what leadership is all about, but for 24 hours he appeared to have caught Mr Brown’s dithering disease.

Now the onus is on David Cameron to show us what he is really made of, and prove that the coalition he and his negotiators worked so hard for can work for the good of the country.

Like the party he has finally led back to power – albeit not outright power – the Conservative leader had to undergo his own process of re-invention.

As he approaches the biggest challenge of his career, he will need to convince voters that the changes are not just skin deep.

For the past few years, he has been seeking to reform the face of his party, breaking the stranglehold of white middle and upper class males by ensuring the selection of more women and ethnic minority candidates through his “A-list” system.

In making changes he consciously sought to echo the transformation Tony Blair wrought on his party a decade earlier.

The reforms have not gone down well in all quarters of the party. Mr Cameron was initially accused by Lord Tebbit of trying to purge all memories of Thatcherism, while others complained of his reliance – like Mr Blair — on a small group of key confidantes and advisers, to the exclusion of outsiders.

We have heard so much talk about the national interest, and we shall soon see what that means.

Anyone who doesn’t know by now that there are “difficult choices” to be made, must have been living on Mars for the past 12 months.

Cuts in government spending will hurt or touch every household in the country. The Cameron/Clegg partnership must stick to their promise to protect the most vulnerable first.

It won’t be a short, sharp shock one crunching tax increase or a couple of major government projects axed. It will be relentless and ongoing, and every government department will be affected despite pledges to maintain frontline NHS provision.

We await with interest George Osborne’s emergency Budget and Liam Fox’s much-needed defence review.

First, however, there will be the appointment of individuals to cabinet and other ministerial posts.

William Hague, by instinct a Euro-sceptic, will be Foreign Secretary; the Lib Dem thinker David Laws, will be given a top job; and Vince Cable, the man who likened Gordon Brown to Mr Bean, will be in the economic mix.

Absolutely fascinating. For the sake of the country, let’s hope members of the first coalition government since 1945 can work together.

It’s a very big ask.