Theresa May launched her election campaign warning about a coalition of chaos and now she is leading one. It won’t work and can’t last. After the election result we have just had, we can’t return to politics as usual with a May-led Tory government. So three things need to happen now.

First we can’t carry on with May as prime minister, propped up by the DUP. The prime minister called an unnecessary election, made it a referendum on her leadership, and then lost. How can she possibly stay in post?

She lacks the skills needed to handle a hung parliament – to be collegiate, to listen, be open and compromise. Much more important, it goes against the national interest for there to be a formal deal between the government and the DUP. The Northern Ireland peace process is very fragile at the moment, with a stand-off under way between Sinn Féin and the DUP. The UK government, which is supposed to be a neutral guarantor, just decided to pick sides.

As for the government’s programme, there is no mandate for cuts to school budgets, ending free school meals or the “dementia tax”. And since a mean and rightwing Tory manifesto has been rejected, it must not be allowed to reinstate it through a backroom deal. What have they promised the DUP? What more will they promise for each crucial vote? Are there any red lines over abortion or LGBT rights?

This deal and this prime minister are not in the national interest and that’s why Labour will keep challenging them and vote against the Queen’s speech next week.

Second, as the political chaos won’t be resolved quickly, we need to find an alternative cross-party way to conduct the Brexit negotiations.

May chose to call this snap election after the article 50 clock started ticking. Negotiations need to start. But they can’t be done by a small Tory cabal. This is the biggest issue for our country for a generation and if the deal is going to be sustainable it needs cross-party support and a broad consensus behind it. After the referendum last year, I called for the government to approach this in a cross-party way to get the best deal. Now it is more important than ever. There is neither strength nor stability in a narrow, bunkered one-party approach; you need to include people with different ideas to get the best deal and widest support.

So we should set up a small cross-party commission to conduct the negotiations, and have a clear and transparent process to build consensus behind the final deal. It should be accountable to parliament but avoid getting caught up in the inevitable hung parliament political rows.

It’s true there is no precedent for this. But there’s no precedent for anything any more. No one will get everything they want. Everyone will have to compromise. But in the national interest we all have a responsibility to work in a grown-up way now over the Brexit negotiations.

Third, we need to be prepared for another general election at any time. We all have an obligation to make work the hung parliament the electorate have voted for. Most people – including probably most politicians, party supporters and journalists – will feel weary at the prospect of yet another poll. But if the government completely unravels, or a new Tory leader wants to gamble again, it could happen at any time.

For Labour that means standing ready to build on the gains and successes of Thursday night, and then go further, winning back places we lost, such as Mansfield, too. Jeremy Corbyn’s campaigning inspired young voters and we need them to support us again, as well as persuading more people to back us in the face of May’s attempt to cling on to power as if nothing has changed.

For the first few weeks of the campaign all we heard was about “strong and stable government”.

Not any more. Business as usual just won’t do as a response to this general election result. For the sake of Brexit negotiations, peace in Northern Ireland and people across the country who voted for something better, politics needs to rise to the challenge and change.