What to expect from Theresa May's Brexit speech in Florence

Speaking in Florence, Theresa May will for the first time explicitly outline her plans for a transition period after departure that could see the UK pay at least 20bn euros to the EU.

But what else could we expect?

Likely is her first admission that the UK will ask the EU for as long as two years to make our complete exit.

Two years during which we might pay billions to keep our existing ties with the single market. Two years, after 2019, that could give business breathing space.

But this could frustrate some voters who chose to leave, who may see departure now only in the distance.

Don't expect chapter and verse on the future relationship. There is not yet a clear agreement in cabinet on its shape and style, even if the prime minister herself had a fully fleshed-out vision.

But there is hope in government circles that the offer could unblock the Brexit negotiations.

There are also expected to be additional guarantees for EU citizens that could help, before the two sides are due to sit down again for official talks next week.

But Theresa May's plea to EU leaders that they have a responsibility to work for a deal could frustrate. For many around the continent, it is for Britain to show its fuller hand.

The prime minister has had to work to keep her cabinet together even thus far.

The journey ahead could promise opportunity, but is packed with political challenges and complication.