David Cameron and Francois Hollande will press ahead with plans to build their own predator drones today, as they conduct their first bilateral talks since the French president took power in 2012.
The two men are trying to advance their military cooperation despite vocal differences over Europe and the economy.
Speaking a joint press conference, the two leaders admitted to their disagreements on the economy and Europe.
"Francois is a French socialist, I'm a British Conservative," Cameron told the press.
"Of course we're not going to agree on everything."
Hollande said: "We are two great countries and we have worldwide responsibilities.
"We are pursuing policies which are not exactly the same but with the same objective – growth and employment.
We are hardly attaining the level of activity from before the crisis. So we have to act nationally and on a European level for more competitiveness and growth. That is in our interest."
The talks will see initiatives on an anti-ship missile system and underwater mine detectors but the biggest announcement comes in the form of a two-year £120 million feasibility study for a combat drone.
BAE Systems, Rolls-Royce and Selex were all involved in the preparatory stages of the project, but there is no confirmation whether they will be involved as it progresses.
The meeting comes a month after all 28 EU countries agreed to cooperate on building surveillance drones to start service in 2020.
Cameron will also use a pub lunch with the president to press his case for a more flexible EU with less regulation, although Hollande is unlikely to help the prime minister much with his mission.
French ministers believe any flexibility for one member state would have to apply to all member states.
The French president is also unlikely to be cooperative given the tit-for-tat criticisms of economic policy he and Cameron have engaged in since he came to office.
The British prime minister publicly endorsed Nicolas Sarkozy at the last French election, only to see his Socialist challenger win the election.
He then said he was rolling out the "red carpet" for any French businesses that wanted to escape the tax increases imposed by Hollande, leading the French president to comment icily on the "British sense of humour".
The break down in relations between the two men put the brakes on the 2010 Lancaster House treaty, which envisioned the two countries sharing defence burdens, including on nuclear weapons and officer exchanges.
Sarkozy and Cameron also had significant differences of opinion on EU issues but the two men managed to put them aside while addressing bilateral issues.
But the value Hollande placed on military cooperation increased after he used a Royal Air Force base in Brize Norton, where the two men are meeting today, in his intervention in Mali a year ago.
The greatest set-back to military cooperation came when Britain U-turned on plans to make its next generation F-35 joint strike fighter able to land on French aircraft, which use a different launching system, due to costs.
Drone technology is increasingly popular in western capitals as a potential means of pursuing military interventions with less risk of domestic loss of life.
The technology is being pursued particularly single-mindedly amid growing signs of public dissatisfaction with British military adventures, not least the decision not to pursue intervention in Syria following President Assad's use of chemical weapons last year.
A recent report by the Ministry of Defence said multiculturalism was a significant factor in the public opposition to conflict, as a war-weary public becomes increasingly uncomfortable with seeing British troops deployed to countries from which they once came.