The number of illegal migrants crossing the Channel is forecast to double this year unless new Government measures can curb the flow, independent modelling shows.

The research, by Richard Wood, one of Britain’s top modelling forecasters, takes account of not only weather and sea conditions but also includes asylum grant rates, illegal immigration flows into Europe, and dinghy size.

His analysis, originally based on five years of data up to the end of 2024, has been accurate in forecasting the numbers reaching the UK so far this year based on “favourable” weather conditions.

More than 23,000 migrants have reached the UK this year, the highest in the first six months of any year since the first arrivals in 2018, which is nearly exactly what Mr Wood’s good weather model predicted.

New migration analysis 

He has now updated his analysis, based on the latest asylum grant rates, increasing dinghy size and immigration flows into the EU, and re-run the modelling based on weather data over the past 16 years.

The data suggest that unless Sir Keir Starmer is successful in his attempt to stop the people-smugglers, migrant crossings will rocket this year.

The Prime Minister has negotiated a “one-in, one-out” deal with France under which illegal migrants coming to the UK will be swapped for people who are able to come to the country legally.

If the weather is as good as it was last year, when there was a surge in crossings in the second half of the year, then the total number reaching the UK by the end of 2025 will be 44,628, according to Mr Wood’s model.

This is just below the number of migrant arrivals in 2022, the highest on record, when 45,774 people crossed the Channel in small boats.

If, however, the weather is as bad as it was in the second half of 2023, then the total number crossing will be as low as 36,965. That would still be the second highest total on record.

New policy benchmark

The data provide a benchmark against which the Government’s new policy measures could be judged to establish whether they have an effect on reducing the crossings.

Mr Wood said: “With the 37th UK-France summit including various deterrent and enforcement pledges for reducing small boat crossings, these predictions may serve as a useful benchmark against which progress can be assessed.”

Mr Wood’s model, currently being peer-reviewed for publication in a migration journal, draws on data from sources including the Met Office, Channel Coastal Observatory, Home Office and European Border and Coast Guard Agency.

It predicts the daily number of small boat migrant arrivals for scenarios based on weather and sea conditions, EU illegal immigration, and other factors which may have a deterrent effect.

It has two parts – the first estimating the probability of a day being “viable”, and the second estimating the number of migrant arrivals on such viable days.

Last week, Sir Keir secured a pledge from Friedrich Merz, Germany’s chancellor, that the country would introduce a new law by the end of the year to enable police to seize boats intended for use by people-smugglers in the Channel.