"Kevin Saunders, former chief immigration officer for Border Force, told Times Radio he was concerned about the lack of a clear plan from Labour on how to stop small boat crossings.
Mr Saunders, a Rwanda scheme supporter, said the plan had caused "unease in the camps in northern France".
"They were very, very worried. And we saw people fleeing to the Republic of Ireland because they didn't want to be included in it," he said."
If the scheme hadn't been hampered by legal challenges, it would have served to reduce the attraction to cross Europe to get here.