Travel firm Tui has made a number of changes to its holiday programme.
Beach holidays up to and including May 14 and Marella Cruise holidays up to and including May 31 will no longer operate.
A spokeswoman said: “We are constantly monitoring the situation and will start taking people on holiday again as soon as we are able to do so.”
Tui revealed trips from June 30 2020 and onwards are currently still set to go ahead as planned.
Jet2 holidays and Jet2.com also say their flights and holidays will resume in June.
The operator released a statement on Tuesday (April 7) to say they had taken the decision to recommence operations on June 17, 2020.
However all bookings scheduled to depart before this date would now be cancelled due to the ongoing coronavirus pandemic.
In a post shared on their official social media channels, a spokesperson said: “In view of the ongoing uncertainty caused by the COVID-19 pandemic, we have taken the decision to recommence our flights and holidays programme on June 17th.
“This means for customers travelling before this date, unfortunately your flights and holidays will not be operating.
“We will be contacting all affected customers to discuss their options, one of which is rebooking to a later date. We are contacting all customers in departure date order which we believe is the fairest way to handle this.
“The number of calls we have been receiving is unprecedented so you do not need to make contact with us. Please do bear with us, and we thank customers in advance for their loyalty, understanding and patience.”