British Prime Minister Theresa May travels to Florence this week to deliver a long-awaited speech on her Brexit strategy. The venue and timing are not ideal — it is a speech she should have given months ago, to a British audience — but if she gets the substance right, she can still help her country to avoid the very worst effects of this unfolding Brexit disaster.

Britain voted to quit the European Union in June 2016. A year passed before talks even began. Since then, three months of negotiations have gone nowhere. The exit procedure sets a deadline of March 2019, but the real deadline is actually six months sooner — just one year from now — because the EU’s other members will have to review and approve any deal. If there is no agreement, Britain is ejected anyway and chaos ensues.

Even now, May has not said what she wants for the exit, for a future partnership with the EU, or for a temporary deal that may or may not bridge the two. And she has not said, one suspects, because she still doesn’t know. Even a well-executed Brexit would still be a bad idea; Brexit done badly will be a shambles of stunning proportions.

The venue for May’s speech is discouraging because the message she most needs to send is not to Italy or Europe, but to her fellow British citizens, and above all to her own party. Three main things need to come through loud and clear.

First: Britain will not quibble over exit payments. This is a trivial matter, she ought to say, not one of pride or principle. Liabilities will be paid in good part. The details should be sent for independent arbitration, allowing the talks to move on.

Second: A transitional deal will be needed because the long-term partnership cannot be negotiated in the time remaining. Moreover, this pact will essentially freeze the existing arrangements, except that Britain will no longer have a vote in EU affairs. This is the price, she should say, that Britain understands it must pay for an orderly departure.

Third: Britain wants the closest possible future partnership with the EU, subject only to remaining an independent sovereign nation, and is ready for the give-and-take that will require. It is not expecting to dictate or demand.

Resistance to all three of these essential elements is most intense in her own party. If it is not already too late, she needs to confront that resistance — right now, and head-on.