As many as 50,000 place-names in the Irish language will not have an Eircode when the new postal and location code system is launched on Monday, a campaign group has said.

Conradh na Gaeilge said there are thousands of inaccuracies and information gaps in the Eircode database. Its general secretary Julian de Spáinn has said the Irish version of many addresses will not be linked to their new Eircode.

Conradh said the problem was acknowledged by the Department of Communications earlier this year and a working group produced an action plan which laid out a programme over two years to resolve the situation at a cost of €200,000.

It has said the department is unwilling to sanction the expenditure.

A spokesman for the department said work on updating the Irish language version was ongoing and pointed out that people would not be required to change address from Irish to English. He also said the use of the postcode was not compulsory.