Mrs May wants to use summit with president Macron to show Britain still has plenty to offer EU as she negotiates Brexit
Britain's May to deepen security ties with France in the hope of Brexit goodwill
Britain and France will agree on Thursday to deepen security cooperation, a move which British prime minister Theresa May hopes will win her goodwill in talks on leaving the European Union.
Mrs May, who was weakened by losing her Conservative Party's parliamentary majority in an election last year, wants to use a summit with French president Emmanuel Macron to show Britain still has plenty to offer EU member states as she negotiates Brexit.
But in talks at Sandhurst, Britain's army officer-training academy, she will be under pressure from Mr Macron to accept more asylum seekers and to pay more for border security on the French side of the Channel.
She may also have to respond to overtures from the EU this week for Britain to change its mind and stay in the bloc, although a government spokesman ruled this out.
"Today's summit will underline that we remain committed to defending our people and upholding our values as liberal democracies in the face of any threat, whether at home or abroad," Mrs May said in a statement.
"And while this summit takes place as the UK prepares to leave the EU, this does not mean that the UK is leaving Europe ... A strong relationship between our two countries is in the UK, France and Europe's interests, both now and into the future."
Neither leader wants the talks to focus on Brexit, with French officials saying the negotiations are led by Brussels, not Paris, and British aides underlining that the summit is about "shared interests and priorities".
Few meetings with Mrs May escape discussion on unravelling more than 40 years of the union. But the two leaders will try to focus on new initiatives to enhance security and defence cooperation, including Thursday's first meeting of the five heads of British and French intelligence agencies.
"Recent terrorist attacks across Europe underline the scale of the cross-border challenge we face in keeping our citizens safe," a spokesman said.
"We will work together to deepen and enhance cooperation on law enforcement, security and criminal justice, to improve the safety of citizens across Europe and to strengthen our internal security capabilities."
The two are also expected to commit to joint military operations including a expeditionary force.
Britain will pledge to send three Chinook helicopters to Mali to provide logistical support for a French counter-terrorism operation and to participate in a new European defence venture, the European Intervention Initiative.
France, in turn, has committed to contribute troops to British-led Nato forces in Estonia in 2019.
But a potentially more pressing issue will be the border between the two countries which, under the Le Touquet agreement, gives Britain a border in France – blamed by some officials for attracting migrants to Calais.
French officials said on Wednesday that the two sides would sign a new immigration treaty to complement the deal and have called on Britain to provide more money and resources to tackle migrant flows.
A spokesman for Mrs May said discussions were continuing but agreed the agreement was "very beneficial to the UK and we value its continuation".
He added: "If there were requests for further help in relation to security we would look at those."
Overall, aides on both sides hope the summit will show the strength of ties between the two countries, something one French official said had become more important after the election of US president Donald Trump.