A government deal over continued EU membership will not be legally binding, according to analysis published today by a cross-party organisation campaigning for ‘Brexit’.

‘An unsigned contract: the legal effect of the renegotiation’, published by Vote Leave, states that any agreement between the government and other EU member states ‘will have the same legal status as an unsigned contract’.

Prime minister David Cameron is this week meeting European leaders. Following discussions with French president Francois Hollande yesterday, a spokesperson for the PM’s office said the pair ‘agreed we are making good progress on the UK renegotiation and that the draft test from the European Council provides a firm basis to reach agreement at this week’s summit’.

However, Vote Leave’s report states that the European Court of Justice (pictured) will only accept a ratified treaty change. The time required for all member states to ratify a treaty means this will not be possible should a UK referendum be held this year.

An intergovernmental agreement, such as one agreed between Denmark and other member states in 1992, would be ignored by the court.

The court would also not necessarily enforce the agreement if it were registered at the UN, says the report.

The group says a political agreement between EU states would have ‘no legal significance’ and that ‘anyone’ would be able to challenge it in the English courts.

Vote Leave chief executive Matthew Elliott said the only way to obtain a ‘legally binding and irreversible’ change to the UK’s relationship with the EU was to vote leave in the referendum.

Elliott said: ‘David Cameron is asking voters to sign up to hand more money and power to Brussels on the back of supposed reforms that will have the legal weight of an unsigned contract.’