Egypt's antiquities ministry has asked the Egyptian embassy in London to take all legal procedures to prevent an ancient statue from being sold in a Christie's auction later this week.
The statue, of Egyptian scribe Sekhemka, was put on Christie's auction list by Northampton Museum and will go on sale in four days.
Sekhemka is a 2300 BC limestone statue from the fifth ancient Egyptian dynasty and depicts the scribe with his wife sitting beside his legs. It is 75 cm tall and 29.5 cm wide.
The statue was a centrepiece at Northampton Museum, which sent it to auction at Christie's in London as part of its exceptional 2014 sale later this week.
Antiquities Minister Mamdouh El-Damati has denounced the sale of the statue and described the museum's actions as incompatible with the values and role of museums worldwide, which he said should "spread culture" and not try to simply earn money.
He called on the International Council of Museums (ICOM) to stop the sale on the grounds that it goes against the council's ethics.
Ali Ahmed, head of the ministry's stolen antiquities section, explained that the Sekhemka statue was given to Northampton Museum at the end of the 18th century by an Ottoman sultan and has been a part of the museum's collection on display since 1849.
The London-based Museums Association has sent a final warning to Northampton Borough Council saying it will review the authority's membership status if it sells off the ancient Egyptian statue.
A petition and a campaign have also appeared on Facebook to stop the sale.