Campaigners fighting the export of a £15.76m statue sold by Northampton Borough Council have called on David Cameron to prevent it leaving Britain.
The statue of Sekhemka was sold to an anonymous buyer in July 2014 but a temporary export ban later imposed.
This will expire on 29 July and British and Egyptian campaigners have asked the prime minister to intervene "urgently".
The department of culture has said the export ban on the 4,000-year-old statue would remain if a UK buyer was found.
Save Sekhemka action groups in Britain and Egypt have challenged Mr Cameron to intervene to save "one of the jewels of Egyptian and world art".
"An export licence would allow the statue to be sent anywhere in the world, possibly never to be seen in public again," a spokesman said.
"The sale by Northampton Council was opposed by the Arts Council, the Museums Association, the Art Fund, and the International Council of Museums, as well as local people in Northampton."
The two groups want the Department for Culture, Media and Sport (DCMS) to broker a binding agreement to keep the statue on free public display in a British museum.
A DCMS spokesperson said: "We hope the export bar will result in a UK buyer coming forward so the statue can remain in Britain.
"The deferral period may be extended if a serious intention to raise funds to purchase the statue is made."
Culture Minister Ed Vaizey placed the temporary export bar on the statue because it is considered to be the finest example of its kind anywhere in the world.
The statue represents an ancient Egyptian official surrounded by his wife, son and seven offering bearers.
Northampton Borough Council said the statue was sold to raise money for museum expansion.