David Cameron is to place security at the heart of the argument for Britain's membership of the EU as he unveils plans to co-operate with France on the development of a new advanced unmanned drone.
The Prime Minister is to hold talks with President Francois Hollande in Amiens at an Anglo-French summit focusing heavily on security and international relations.
The two leaders will reaffirm their commitment to wage a "relentless" battle against the threat of international terrorism in the wake of last year's attacks on Paris which left 130 dead and hundreds more injured.
This will include intensifying police and security co-operation with enhanced information sharing between security forces and making full use of the Interpol lost and stolen travel documents database and the Schengen information system.
Pro-Brexit ministers like Iain Duncan Smith have argued that Britain's membership of the EU - and the commitment to free movement of people - leaves it exposed to the danger of a Paris-style attack.
However Mr Cameron will use the gathering to emphasise that being in the EU actually strengthens UK security while boosting its ability to project power around the globe.
"The UK and France are proud allies. Our meeting here in Amiens today is an opportunity to discuss how we can work even more closely together to keep our people safe," he said in a statement ahead of the talks.
"I am convinced that the UK's membership of the EU gives us greater security and greater capacity to project power globally. In an ever more uncertain world, we gain from our membership of these international organisations."
The two leaders will also announce £1.5 billion of investment in a joint project to build a prototype of the next generation of unmanned military drones described as the most advanced vehicle of its kind in Europe.
It follows a £120 million feasibility study for the Future Combat Air System launched at the last UK-France summit two years ago.
The talks - which will be attended by Foreign Secretary Philip Hammond, Home Secretary Theresa May, Defence Secretary Michael Fallon and their French counterparts - will also cover the migration crisis and the conflicts in Syria and Libya.
Downing Street indicated the premiers will discuss the situation in Calais, after Mr Cameron claimed that France could stop allowing UK border checks on their side of the Channel if Britain votes to leave the EU.
The PM has also confirmed he wants to speak to Mr Hollande about the Hinkley Point C nuclear power plant, due to be built in partnership with French firm EDF Energy. There have been calls for the project to be delayed over fears of reactor design flaws.