On numerous occasions following the referendum result, business groups have called for clarity on Britain’s future and an end to uncertainty.

They have claimed that uncertainty would lead to the dire consequences of disinvestment and a run on the pound, with consequent impact on employment and leading to a recession.

Of course none of this has happened in spite of the reality that the very policies pushed by groups such as the CBI have led to a weakened negotiating position on the part of the UK government, consequent time wasting and mounting uncertainty.

Nonetheless, business does not like uncertainty and as the date of leaving approaches uncertainty will mount exponentially, the consequences of which could produce actual damage.

A further period of “transition” without any certain outcome would add substantially to this and the longer it goes on, the worse will be the effect.

Now is the time to end uncertainty and the tools to do this lie in the hands of the Conservative Party, but they must act now or face electoral oblivion.

Firstly, the Brexit supporting MPs of the Conservative Party must put in letters to the 1922 Committee Chairman and force a leadership challenge.

Hitherto, reluctance to do this has been based purely on concern the “blancmange” of MPs occupying the “career first” centre ground will vote the wrong way, the PM will survive and they will be stuck with her for another year.

However, even such an outcome is preferable to the certainty of being stuck with her anyway and thus perpetuating the uncertainty she is creating.

Even a leadership challenge which fails, creates the certainty that there are sufficient MPs dissatisfied and prepared to act that there is absolute clarity as to what will and will not be acceptable to Parliament. In any event they may succeed. The greatest risk is not to act at all.

This course of action will produce either a change of PM or a change of policy, and preferably both, in which case the UK should then make it clear that we are leaving the EU on March the 29th 2019 without a transition period. This would provide absolute certainty to business and five months to prepare.

Secondly, the above should be accompanied by the sacking of the Chancellor and the appointment of a new negotiating team.

Thirdly, the government should declare at the same time as to its resolve to just leave, a package of economic stimulus and business friendly tax and spending measures and commitments, using the saved £39 billion and future savings of net contribution, a considerable sum, along with selective removal of external tariffs.

It should also promise regulatory reform in areas such as financial services, data, biotech, innovation, healthcare and manufacturing.

All in all, these measures will suddenly change the landscape of opinion in even the corporate business community, produce an immediate fillip to growth and more than cancel out the negative effects of short term disruption.

The alternative will be a failure to deliver Brexit, a massive fraud on the electorate and betrayal of democracy, the consequences of which will be incalculable but at least will result in a Corbyn government and wilderness years for the Conservative Party.

By these measures not only can we guarantee the much sought after certainty that business calls for, but also a bright future for business Britain and for the economy. It will require courage and leadership.

It starts with the removal or corralling of our duplicitous and weak PM. Enough is enough, now is the time to act before it is truly too late to save Britain from the eternal tyranny of the EU.

John Longworth is an entrepreneur, Chairman of Leave means Leave and is on the Advisory Board of a Economists for Free Trade and the IEA. He was formerly Director General of the British Chambers of Commerce.