The four-nation Eurofighter consortium was dealt a heavy blow last week when Singapore's defence ministry told the group it had uncovered problems that could prevent the government buying the jet.

According to people familiar with the decision, Singapore has stopped short of dropping Eurofighter from a three-way competition. But it has raised detailed questions about the ability to fit Singapore's advanced weapons on the jet, a stumbling block that may make it impossible for Eurofighter to win.