The foreign office is pressing for a key border point in Gaza to be reopened to allow British nationals to leave the bombarded territory.
Almost 90 people with a British passport or UK travel documents had formally requested to pass through the Rafah crossing on Saturday into Egypt, according to a list produced by the authorities running the border post.
But UK nationals found themselves turned away, with the crossing shut to foreign nationals over a reported row over evacuating injured patients.
The Rafah crossing is the only route out of the territory for foreign nationals and the sole entry point for incoming aid.
Zaynab Wandawi, 29, from Salford in Greater Manchester, and a group of 12 family members – 10 of whom are British nationals – were told they were on the list on Saturday, according to her mother, Lalah Ali-Faten.
But the English language teacher was turned away from the border owing to disagreement between authorities in control of the crossing.
A spokesman for the Foreign, Commonwealth and Development Office said it was “disappointed” that the vital border post had been “temporarily closed”.
“This continues to be a complex and challenging situation and we are using all diplomatic channels to press for its reopening in co-ordination with our international partners,” the spokesman said