WARSAW, Poland — The Bulgarian Ministry of Defence has amended the technical specification of its fighter jet tender in a way that favors the purchase of used F-16s from Portugal, Bulgarian lawmakers have revealed to the country's parliament.

At a meeting of the parliament's Defence Committee, Atanas Zafirov, a member of parliament for the opposition Bulgarian Socialist Party (BSP), asked Defence Ministry officials whether it was true that the revised tender criteria reduced the maximum amount of weighed points allocated according to the aircraft's service life from 25 percent to 0 percent of the total, as broadcast by local TV channel Kanal 3.

The new criteria are expected to be approved by the end of this week by the country's Defence Council, a body which brings together the Bulgarian minister of defense and the country's top military officials. Afterward, the ministry will send out invitations for bidding to the interested parties.

The criteria of the contest that will pit the F-16 against Saab's JAS-39 Gripen and the Eurofighter Typhoon aircraft were changed following the departure of former Air Force chief Gen. Rumen Radev when he retired from his post. Last August, Radev announced his decision to run for president in the Nov. 6 election with the support of the BSP.

Bulgaria wants to replace its aging fleet of Soviet-designed Mikoyan MiG-21 fighter jets with new aircraft. The Defence Ministry plans to allocate about 1.5 billion lev (US $839.8 million) for the acquisition.