The number of people prosecuted for smuggling illegal immigrants into Britain in their vehicles has risen by more than 50% in a year, according to new figures.

Home Office statistics show that 88 people were prosecuted for bringing stowaways into the UK in 2015-16, compared to the 52 taken to court the year before.

The figures come amid concern that the migration crisis has driven larger numbers of people into the hands of smugglers, risking their lives in the back of vans and lorries to make the journey to Britain.

Keith Vaz, the chairman of the home affairs select committee, said many more people smugglers were going undetected.

He said: “We welcome the increase in the number of prosecutions. However, based on the number of illegal immigrants who have entered the country, this is only the tip of the iceberg. We need to be tougher on enforcement rather than what we have done before which is to send vans around telling people to leave the country.

“It’s vital we send out a strong message to those who are smuggling people into this country that we will not tolerate such criminality. The best way to do that is to increase not just the number of prosecutions, but the penalties of those who have been involved in smuggling.”

The prosecution figures emerged in an answer to a parliamentary question asked by the Labour MP Gareth Thomas.

It is not known how many illegal immigrants are living in the UK but a report produced by the LSE estimates there are between 417,000 and 863,000.

As hauliers and drivers have faced prosecution, there is growing evidence that people smugglers are increasingly turning to small boats and dinghies to bring illegal immigrants to British shores. In May, 18 migrants were discovered in a dinghy off the Kent coast near Folkestone.

The National Crime Agency has warned that criminal gangs have started targeting quieter ports on the east and south coasts of Britain.

Meanwhile, there has also been a dramatic rise in the number of fines handed to employers for hiring illegal immigrants, with the number doubling in three years. Some 2,594 fines were given in 2015-16 – more than double the 1,270 issued in 2012-13, although the figure is only slightly higher than the 2,339 given in 2009-10.