Twelve more migrants in two separate boats have been detained off the coast of Dover as the local MP questioned why there was not more security in France.
At about 03:00 GMT HM Coastguard received reports of a dinghy containing four men approaching the coast.
Six hours later the Maritime Intelligence Bureau was notified of a small boat carrying Iranian men.
Immigration Minister Caroline Nokes said they were "working closely" with their French counterparts.
All of the migrants were taken to Dover and given a medical assessment before being transferred to immigration officials to be interviewed.
In the first boat, one of the adults was found to be Syrian, the rest were Iranian.
'Returned to France'
Damian Collins, MP for Folkestone and Hythe, said: "We need to make it really clear to the migrants and the gangs that if you try and do this you will be detected early, either as you're preparing to leave or as soon as you're in the water you'll be returned to France.
"But I think we should be working with the French Authorities on policing that, and making that happen. But also understand why is it these people are not in the asylum system already? Why have they not claimed asylum?"
As of 28 December, at least 221 people, including 14 children, had crossed the Channel in small boats since 3 November.
Mr Collins added: "We're quite good at spotting vessels approaching the UK and either bringing them in, escorting them in, or having Border Force agents waiting for them when they land.
"This is the busiest shopping lane in the world and it's probably the most closely monitored. But what I don't understand is why are we not doing more to stop the boats leaving France in the first place?"
Bridget Chapman, from Kent Refugee Action Network, said the UK paid to "beef-up" the security around Calais, including the putting up of a large fence to prevent people accessing trains and lorries.
She said that had made people "resort to other methods to get here", adding: "I expect people traffickers are exploiting people, saying, you know, things are going to tighten up after Brexit, you need to go now."
Immigration Minister Caroline Nokes said: "The number of incidents over recent days is deeply concerning.
"Some of this is clearly facilitated by organised crime groups while other attempts appear to be opportunistic."
She said UK authorities were working closely with their French counterparts in a recently-opened joint intelligence centre in Calais to target people smugglers.
She reiterated that attempting to cross the Channel in a dinghy was "extremely dangerous" and warned that people were putting their lives at risk to do so.
The people found off the Kent coast since November:
- 27 December - Some 23 migrants, including three children, were detained in Kent after crossing the channel in small three boats
- 26 December - Three migrants brought ashore by Border Force
- 25 December - Forty migrants, including two children, crossed the Channel in five boats
- 15 December - Four children are among a group of 11 people rescued off Dover. Eight said they were Iraqi and the other three claimed to be Iranian
- 12 December - Six men found in a dinghy off the coast of Dover
- 11 December - Six people, thought to be from Iran were rescued from a small boat off the Kent coast. A second boat with eight men, all saying they were Iranian were picked up later the same day off Dover
- 4 December - Two men were brought to shore at Dover
- 27 November - An 18-month-old baby was among nine people rescued from a dinghy off Dover
- 23 November - Eight men located in a dinghy off the coast of Dover
- 22 November - Thirteen men and one woman were intercepted in two dinghies off the coast of Dover
- 18 November - Nine suspected migrants were found clambering up rocks in Folkestone after apparently crossing the English Channel in a small boat
- 16 November - Seven suspected migrants were found off Samphire Hoe, near Dover
- 14 November - Nine suspected migrants - seven men, one woman and a toddler - were found off the Kent coast. Another 10 were found near Dover Docks and five men were found several miles of Ramsgate
- 13 November - Fourteen men and three children entered Port of Dover on a French fishing boat believed to be stolen
- 9 November -Seven men were found in the English Channel off Dover
- 3 November - Eight suspected migrants were stopped off the Kent coast and seven others were stopped at Dover Western Docks
A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.