Ministers will set out plans tomorrow which could see Britain take in some of the most vulnerable refugees from the civil war in Syria.
Downing Street said an announcement will be made before a House of Commons debate called by Labour, which wants the UK to sign up to a United Nations programme to provide sanctuary for up to 30,000 refugees in Western nations.
Prime Minister David Cameron has refused to accept a "quota" of refugees under the UN scheme, but last week told MPs that Britain was ready to consider taking in people in cases of extreme hardship.
He stressed that Britain was already the world's second-largest bilateral donor in the crisis, providing £600 million to help victims in Syria itself and neighbouring countries
Home Secretary Theresa May told MPs that she was working with Foreign Secretary William Hague on "further support" which could be offered to refugees.
Now, Prime Minister David Cameron's official spokesman has told reporters: "As the Home Secretary set out in the House, there will be an announcement in time for tomorrow's debate. We are continuing to work on the proposals and we will set them out in time for tomorrow's debate in the House."
No details were available of how many Syrian refugees might be accepted by the UK or how they will be selected. It is thought that those admitted to the country are likely to include children in need of urgent medical treatment or mental health support which is not available in the camps which have sprung up in Syria's neighbours, such as Lebanon.
Liberal Democrat Deputy Prime Minister Nick Clegg is understood to have been privately telling Mr Cameron that there is an "overwhelming" moral case to accept refugees, while Labour argues that "several hundred" should be let into the country.
France has agreed to take 500 refugees under the scheme and Germany has accepted 1,000 with a promise of admitting another 9,000.
At last week's session of Prime Minister's Questions, Mr Cameron said: " I don't believe you can solve a refugee crisis of this scale - when you have got almost half of the nine million population of Syria either displaced or at risk of displacement - with a quota system where countries are taking a few hundred refugees.
"But I do agree if there are very difficult cases of people who don't belong in refugee camps who have either been disabled by these attacks, or in very difficult circumstances, I'm happy for us to look at that argument. Britain always plays the right role in these desperate humanitarian crises."