Nearly 1,000 illegal migrants have crossed the Channel by small boat this month, Border Force figures show, double the number last month.
Border Force intercepted 179 people attempting the dangerous 21-mile journey in six boats on Wednesday, bringing the total for June so far to 998.
That is more than double the 407 who crossed in the same period last month, which ended up as a monthly record with 1,619 migrants arriving in 80 boats.
It brings the total so far this year to 4,752, already more than half the record 8,713 last year.
Border Force is believed to be preparing for an influx of migrants over the next few days due to near perfect weather conditions at sea.
It comes amid growing public concern at the failure of the Government to stop the surge in migrants despite the UK handing £100 million to the French to boost surveillance, put more officers on the beaches and institute camp clearances.
Nearly two-thirds – 65 per cent – of 3,000 adults polled recently by YouGov felt the Government was handling immigration badly, the highest dissatisfaction rating since last Autumn when migrant crossings also hit a peak.
Concern about immigration in the wake of the surge in illegal migrants crossing the channel is now on a par with climate change as one of the three most important issues that the public sees as facing the country, behind only the economy and health.
Home Office figures show that the number of asylum seekers returned last year after having their claims rejected fell to 1,546, down 53 per cent compared with the previous year.
This is down from a high of 15,000 in 2004, a decline blamed on the growth in legal appeals by failed asylum seekers that can bog down attempts to remove them for months, if not years.
The Government has also reduced the number of failed claimants being held in detention, which means thousands of asylum seekers have gone missing.
Alp Mehmet, chairman of Migration Watch UK, said: "Public confidence in the government and their ability to deal with illegal immigration has plummeted. No wonder, given their record in the Channel and on immigration control generally, which has been abysmal.
"Essential enforcement has crumbled and we are a million miles from the controlled immigration we were promised. Instead of improving, the situation gets worse by the day."
A Home Office spokesman said: "Criminal gangs are putting profits before people’s lives through these dangerous and unnecessary crossings.
"More than 4,000 people have been prevented from making the dangerous crossing so far this year and we are cracking down on the despicable criminal gangs behind people smuggling.
"Inaction is not an option whilst people are dying. The Government is bringing legislation forward through our New Plan for Immigration, which will break the business model of these heinous people-smuggling networks and save lives."