Britain's Prime Minister Theresa May speaks to members of the Charity Commission for England and Wales at The Royal Society in London, January 9, 2017.

Prime Minister Theresa May will call on Britons to reject the acrimony of the Brexit referendum in a speech this week that some newspapers have billed as setting the stage for a "hard" exit from the European Union.

Investors will scrutinize May's speech on Tuesday for clues on whether she plans to prioritize immigration controls and bilateral trade deals in a "hard Brexit" that would see Britain leave the EU's single market and customs union.

May intends to launch by the end of March the formal process of negotiating the terms of Britain's exit from the EU, but has so far given very little away about what deal she will be seeking, frustrating some investors, businesses and lawmakers.

May's speech will stress the need for Britons, who voted for Brexit by 52 to 48 percent in last June's referendum, to unite around common goals such as protecting and enhancing workers' rights, her Downing Street office said in a statement.

"Now we need to put an end to the division and the language associated with it – 'Leaver' and 'Remainer' and all the accompanying insults – and unite to make a success of Brexit and build a truly global Britain," May is expected to say.