Who would have thought? The Conservative party, the party of continuity and tradition, is now the cause of the greatest constitutional crisis in modern times. The party of business is now the source of reckless economic turmoil. The natural party of government is now presiding over paralysis in Westminster and Whitehall. The party of the British bulldog spirit is now leading our great country towards rudderless introspection.

There is something almost grotesque in the contrast between the self-indulgence of the Conservative leadership contest and the anxiety gripping millions of families worried about the future. The media swarms around Michael Gove’s self-absorbed pronouncements justifying the tawdry betrayal of his friends.

A nervous nation, unsure what it has done to itself, is subject to the tedious, vituperative comments from one Conservative nonentity about another. No wonder Theresa May – a diligent, hard-working if unimaginative politician – stands out as a grownup in that political playground.

This cannot go on. Somehow we must navigate the country through the months ahead. The government not only finds itself without leadership, it has no plan, no consensus and no clue about what it wants to do in the future. The only thing it agrees on is that the UK should leave the EU. But how, when and to what end all remain unanswered. It enjoys a mandate to quit, but no mandate as to how this should be done.

This is partly the result of the unforgivable cynicism of a Brexit campaign that refused to tell voters what comes next. But it is also a consequence of contradictory opinions: the hedge fund owners who financed the campaign want to turn the City into a low–regulation Dubai; Boris Johnson wanted to open Britain to far-flung continents; Michael Gove wants to close Britain against incomers; and most Brexiteers witter about maintaining access to the single market while not being subject to its rules, apparently oblivious to the glaring contradiction.

This debilitating cocktail of hubris, incompetence and dishonesty must be overcome if the country is to move forward. This is what we should do.

First, each Conservative leadership candidate must set out, in detail, what they think our future relationship with Europe should be. Second, the new prime minister, to be announced on 9 September, should immediately publish a white paper setting out a full plan. And third, he or she must then seek a democratic mandate for their plan in an early general election.

The notion that it should be left to Conservative members to handpick a new prime minister for what in effect will be a new government pursuing new priorities is absurd.

This election would also give all parties the opportunity to set out their stalls on what our new relationship with Europe should be. As Tim Farron has made clear, the Liberal Democrats will fight that election on a patriotically pro-European platform. Labour, whether under Jeremy Corbyn or not, will need to make up its mind.

Importantly, the election must be held before any attempt is made to activate article 50, the legal mechanism triggering the negotiations for EU exit. Starting that clock ticking before people have had an opportunity to cast a judgment on what life would actually look like outside the EU would be deeply undemocratic. The Fixed-Term Parliaments Act 2011 envisaged exceptional circumstances in which an early election can be held, and those provisions should be invoked.

The baton then moves to the newly elected parliament. It will have two tasks: MPs must scrutinise the government’s specific plan to ensure it is legal and workable, and, crucially, article 50 should only be triggered following a vote of consent from MPs. Some have argued that the prime minister can invoke article 50 on her/his own, using royal prerogative powers. Many top legal experts, including Lord Pannick and Lord Lester, disagree.

In any event, there is recent parliamentary precedent. Under the Lisbon treaty, the UK was granted the right to a “mass opt out” from EU laws governing police and judicial cooperation. In the coalition government, both parties agreed to exercise this power, while negotiating to preserve the most important crime-fighting measures, such as the European arrest warrant. We went to parliament to seek a mandate for those talks in 2013, and returned again to parliament in 2014 to seek approval for the package we had negotiated.

If a vote at the beginning and the end of a negotiation was good enough for a specific area of EU policy, it should also be good enough for the complete decoupling of the UK from the EU.

Finally, the definitive, negotiated terms both of our exit from, and our future relationship with, the EU must then be put back to parliament for a vote of consent.

The EU referendum has exploded constitutional, political and economic conventions. Our country is in a tailspin. An election of a new parliament in which MPs act responsibly to manage our historic divorce from the EU is the only way to forge some order out of the present chaos.