Booking.com has continued to allow people to reserve accommodation during the lockdown, despite government advice that bookings should not be accepted.
Yesterday, the company had 272 properties available to book in the Highlands, as well as 59 in Perthshire and 230 in Edinburgh for two people staying overnight on Saturday 25 April, according to a report in The Herald.
SNP Westminster leader, Ian Blackford, who represents Ross, Skye and Lochaber, has previously called for emergency laws to be introduced to stop second home owners heading to the Highlands to self isolate.
Mr Blackford told the newspaper: "It is astonishing that holiday rental companies continue to advertise and let out properties during this state of emergency.
"People are being told to stay at home and avoid any unnecessary travel.
"Those who flout the rules and go on such vacations are putting people's lives at risk - particularly in communities where there are geographical pressures.
"Booking.com is acting irresponsibly - no one should be putting profits before people's lives."
Lib Dem MP for Caithness, Sutherland and Easter Ross, Jamie Stone, has now written to the Prime Minister, calling on him to put pressure on the company to halt the practice.
Mr Stone said: "Booking.com are highly irresponsible for taking bookings in the Highlands. While we all pray that the pandemic will come to an end soon, we cannot be sure when this will happen. Sadly it could be many months.”
Holiday accommodation site Airbandb last week halted bookings in the UK, except for accommodation needed by key workers, for the duration of the goverment lockdown.
UK Tourism Minister Nigel Huddleston has written to mainstream online booking platforms, instructing them to adhere to the guidance.
He said: “I expect all providers to do the same and not take any non-essential bookings while social distancing guidance remains in place.”
“It is incredibly irresponsible, and dangerous, for some property owners to be marketing themselves as ‘isolation retreats'."
The Scottish Government said travel companies were expected to act responsibly and not take holiday bookings.
A spokesperson from Booking.com said: “During this rapidly evolving time, Booking.com is committed to featuring information across its site reiterating to customers that there are currently travel restrictions to consider in many destinations.
“We have also set up tools to make it easier for accommodations to provide clear information to guests about what national and local measures mean and to indicate any conditions that may apply, including requiring proof of essential travel where relevant.