Each member of the European Parliament gets £3,841, or 4,342 euros, every month which is meant to go towards expenses and includes funding an office in their own country.
But an investigation by The MEPs Project – a freedom of information initiative set up by journalists – found offices for 249 members do not exist, could not be located or requests for the address were refused.
So far just 133 out of the 748 MEPs have revealed what they pay in office rent.
The findings come as European Commission President Jean-Claude Juncker last week branded MEPs “ridiculous” after 96 per cent failed to turn up to hear Joseph Muscat, the Prime Minister of Malta, deliver a speech in the EU Parliament in Strasbourg.
MEPs receive a General Expenditure Allowance (GEA), costing the EU £35million a year. It is to help pay for national offices as well as sundries, like phone lines.
However, research across the 28 member states by The MEPs Project found 41 cases where they pay rent to national political parties or even to their own personal accounts.
As the EU Parliament does not audit the use of these expense payments, no data is available on how the funding is used.
It also does not monitor the existence of the MEPs’ national offices. For the study, information was requested from all 748 MEPs and documents were analysed from the EU parliament, land registries and other sources.
As of June 1, only 53 have said they would be willing to share documents on their public spending.
In Germany alone, eight MEPs from several parties were the owners of the buildings where their national offices were located.
Among them was Manfred Weber, chairman of EPP, the biggest group in the EU Parliament. His office is in an annex to his home in a village in Bavaria. He did not answer questions about it.
The Project found other MEPs – in Belgium to Bulgaria, Italy, Germany, the Netherlands and Spain – do not seem to maintain any national office.
Official guidelines state that national offices, financed with the parliament’s money, “must be used solely for the parliamentary activities of the MEP”.
In April, parliamentarians voted down amendments asking for more transparency or at least random checks on the use of the GEA.
EU Parliament spokeswoman Marjory Van Den Broeke said: “The fact it’s a lump sum means MEPs do not need to hand in invoices or other bills. This also means that the European Parliament administration does not have any information on any offices used by MEPs.”
Wouter Wolfs, a researcher in European politics at Belgium’s Leuven University, said: “There is no transparency for the public.”