Foreign Secretary Philip Hammond is to address MPs on the situation in Libya, a day after he visited the troubled north African state in a show of support for its new government of national accord (GNA).
Mr Hammond will make an oral statement to the House of Commons on Tuesday afternoon amid growing speculation that as many as 1,000 British troops may be asked to take part in an international military force in the country.
Defence Secretary Michael Fallon told the Commons on Monday that the Government "are not contemplating at the moment" the deployment of forces on the ground in Libya.
Mr Fallon said the UK had indicated it was ready to be part of a Libyan international assistance mission, but insisted it was "too early" to say what kind of assistance Tripoli would seek in its fight against Islamic State militants.
The Defence Secretary said ministers would come to the House before any future deployment of military forces in a combat role in a conflict zone.
But he also announced that it had been decided not to enshrine this convention in law, and made clear the Prime Minister reserved the right to take military action without prior parliamentary approval in emergency situations.
Mr Hammond's unannounced visit on Monday came ahead of a meeting of EU foreign and defence ministers in Luxembourg to discuss Libya later that day.
The Foreign Secretary said Britain was ready to provide training support to the armed forces of prime minister designate Fayez Serraj's fledgling administration. He stressed that a non-combat role of this sort would not require a Commons vote.
Mr Hammond briefed David Cameron and senior ministers on his visit to Libya at the weekly meeting of Cabinet in 10 Downing Street
The Foreign Secretary said Mr Serraj had made clear there was "no specific request at this stage" for military assistance from overseas, and had stressed that he wanted to undertake a "Libyan-driven approach" to restoring stability and security in the country.