BAA, which owns Heathrow Airport, made the following statement:
"Immigration waiting times during peak periods at Heathrow recently have been unacceptable and we have called on the Home Office to address the problem as a matter of urgency.
"There isn't a trade-off between strong border security and a good passenger experience - the Home Office should be delivering both."
Long queues had formed at passport control on Thursday and Friday.
More top news
A man who fired at officers from the National Crime Agency has been convicted at the Old Bailey.
Want to know its posh name? It's a 'Track Retrieval Device'.
Unite said its members in the capital's 18 bus operators had supported walkouts by 85%, and action short of a strike by 9-1.