Ministers will spend an extra £100m on measures to deter Channel crossings, including on the planned “one in, one out” returns agreement with France, the Home Office has said.

In a third immigration policy pledge within 24 hours, the home secretary, Yvette Cooper, said the money would pay for up to 300 more National Crime Agency officers, as well as new technology and equipment to step up intelligence-gathering on people-smuggling gangs.

For seven years, successive governments have tried and failed to stop people crossing the Channel in small boats. Figures released last week showed more than 25,000 people had arrived in the UK via small boats in 2025 so far, a record for this point in the year.

Protests outside hotels housing asylum seekers spread this weekend. Nine people were arrested on Saturday in Islington, north London, after brief clashes between protesters and counter-protesters outside the Thistle City Barbican hotel.

On Sunday afternoon, more than 100 people, many of them women wearing pink T-shirts, gathered outside the Britannia International hotel in Canary Wharf after reports that asylum seekers had been bussed in under the cover of darkness. Grainy footage on social media appeared to show men getting off a coach and being escorted into the hotel in the early hours.

A group of men wearing face masks were also seen outside the Britannia hotel later in the afternoon. Chants of “send them home” broke out.

Protesters jeered at people going in and out of the hotel, and officers were forced to step in after flares were let off in the crowd, the Metropolitan police said.

A group of people were “harassing occupants and staff” and trying to prevent deliveries being made, the force added. They were also trying to “breach the fencing and access the hotel”.

One man had been arrested in Canary Wharf “on suspicion of assaulting an emergency worker” after an officer was pushed, police said.

Fresh protests had erupted on Thursday outside a hotel in Epping, Essex – the latest in a series of demonstrations after an Ethiopian asylum seeker was charged with sexual assault against a local girl.

The “one in, one out” deal agreed with France last month means the government will for the first time be able to send people back there in exchange for asylum seekers with links to Britain.

The scheme is uncertain in scale and timing – critics have claimed it will not be a deterrent because it will only result in the exchange of up to 50 people each week.

In a statement, Cooper said the additional funding would “turbo-charge the ability of our law enforcement agencies to track the gangs and bring them down, working with our partners overseas, and using state-of-the-art technology and equipment.

“Alongside our new agreements with France, this will help us drive forward our plan for change commitments to protect the UK’s border security and restore order to our immigration system.”

In a separate development, academics at the University of Oxford have concluded that £20bn has been spent on “migrant-welcoming schemes”, including asylum accommodation, over 10 years, but with little focus on integration and community cohesion.

A team from the Centre on Migration, Policy and Society (Compas) said the money from 26 different spending streams over the decade to April 2024 included a £10bn overspend on asylum accommodation, while only “small amounts of money” had been spent on long-term goals such as community consent.

Jacqueline Broadhead, a senior researcher at Compas, said the government had an opportunity to redress the balance.

“While there have been very high levels of overspend on asylum hotels, there has not been equivalent investment on cohesion and integration, which could help mitigate some of the pressures on local communities,” she said.

On Saturday, the government released plans to introduce a new offence for advertising irregular small boat crossings under the border security, asylum and immigration bill going through parliament.

Assisting illegal immigration to the UK is already a crime. Officials believe the offence would give police and other agencies more power to disrupt criminal gangs.

And in yet another announcement on Saturday, Cooper said she planned to introduce a fast-track scheme to tackle the asylum backlog, with the aim of turning around decisions within weeks.

There are tens of thousands of refugees who have been waiting for longer than a year for an initial decision on their applications for asylum. More than seven in 10 are eventually granted permission to stay in the UK.

The Conservatives criticised Cooper’s funding announcement as a “desperate grab for headlines, which will make no real difference”.

Kemi Badenoch, the leader of the opposition, told Trevor Phillips on Sky News that Labour should revive Boris Johnson’s ditched £700m plan to send people to Rwanda, and should close the hotel in Epping.

“What we need is a third-country deterrent so that people can be processed elsewhere,” she said.