European parliamentarians want to check whether Qatar unduly influenced a key air transport agreement that grants Qatar Airways unlimited access to the EU market and are exploring ways to slam the brakes on the lucrative deal.

Since Friday, Brussels has been convulsed by accusations that the Gulf emirate bought influence in the European Parliament. Former Parliament Vice-President Eva Kaili is the biggest name to be arrested in a police dragnet that has also landed three other people in jail. More than €1.5 million of suspected payments have been recovered.

Karima Delli, chair of Parliament's transport committee which negotiated the deal, has raised the alarm in an e-mail obtained by POLITICO. Delli, a French MEP from the Greens group, warned that Qatar may have interfered in Parliament's internal deliberations on the agreement.

"Given the recent developments, granting the consent to this agreement at this stage could be difficult until it is established that conditions were transparent and unbiased," she wrote in a letter to political group coordinators in her committee.

Delli said that the committee would work with European Parliament President Roberta Metsola's internal investigations by declassifying documents and statements "related to Qatar, if they are requested."

In terms of potentially not ratifying the agreement, which was concluded last year, she added that the committee should seek guidance from the European Commission "to rapidly inform us about the ongoing ratification process of the EU-Qatar Air Agreement and to let us know when the consent procedure is expected to start."

Delli said she was shocked by the revelations of payments being made by Qatar. "It goes without saying that I endorse every word of President Roberta Metsola yesterday. She rightly reminded us that 'We are under attack!'. I share her desire to shed full light on the interference and corruption allegedly organized by Qatar within our institution." 

The EU-Qatar aviation negotiations were heavily criticized at the time by European airlines which feared unfair competition from Qatar Airway's flight connections to destinations throughout Asia, as well as by Qatar Airways' direct Gulf competitors, whose connections to Europe remain capped.

The deal replaces a series of bilateral agreements, and was sold by its backers as a way of ensuring fair competition and common social and labor standards. However, it was condemned by parts of the European aviation sector.

“The agreement with Qatar is neither in the interests of European employees nor of the European aviation industry,” Maria-Pascaline Murtha, board member of German pilots union Vereinigung Cockpit, said last year when the deal was signed.