The European Investment Bank (EIB) must explain whether it considered UK jobs when it loaned Ford motor company money to develop its Turkish factory, Catherine Bearder MEP has said.
Last week it was announced Ford plans to close its Southampton plant in July with the loss of 500 jobs.
Now Catherine has pledged to find out if EU cash paid to the firm just before it decided to shut Swaythling was used to boost production in Turkey.
It appears an £80m EU loan was used to improve production of the Transit van at the factory, even though it is not based in an EU member state.
She said: "These job losses are very disappointing. They will have a huge impact on Southampton and the local economy.
"I can't understand why the EIB appears to have allocated funding in direct competition to jobs within the European Union.
"I will be questioning the people behind the decision to find out if the job losses in Southampton, Dagenham and Belgium were factored in when the cheque was written."
Catherine said the EIB should have sought guarantees over the protection of UK jobs before signing off the loan.
Turkey is an associate member of the European Union, but is currently negotiating to become a full member.