A Downing Street spokesperson said:

The Prime Minister called European Council President, Donald Tusk, earlier this evening to take stock of progress ahead of tomorrow’s European Council.

The Prime Minister thanked President Tusk for the European Council’s hard work. They agreed that good progress had been made in all 4 areas of our renegotiation and that the draft texts presented a good basis for agreement at tomorrow’s European Council, subject to the satisfactory resolution of outstanding issues. They looked forward to continuing the discussion at their meeting ahead of the Council tomorrow afternoon.