Brussels wants to make it easier for EU architects to work anywhere in member states, including the UK, and is forcing through a major shake-up of the Architects Act 1997.
This would mean British firms would be forced to automatically recognise migrants' overseas architectural qualifications from 20 October this year - a move rubber-stamped by the ARB.
The highly controversial move annuls an approved list of 'visiting EEA architects' drawn up under the Architects Act 1997.
European Directive 2005/36/EC for Architects - released by the Department for Communities and Local Government (DCLG) last week - exempts EU migrants from registering with the ARB providing they are working in the UK on a 'temporary or occasional' basis. Significantly, the Directive does not specify a time limit for casual employment.
Migrants need only prove EU nationality and 'lawful' employment history to gain a job in the UK. And they won't even need to speak fluent English - this will be left to the discretion of individual UK employers.
According to the Directive, 'The fact that a service provider is lawfully established in another member state is all that is required'.
It continues: 'Architects are excluded from producing qualifications because they are not a profession having direct Health and Safety implications.'
The ARB will be able to independently register a migrant in order to discipline, but the board will not be permitted to charge for this - a condition that has infuriated long-term ARB critic Ian Salisbury.
Salisbury said: 'Temporary registration in this country and no fee. So who pays? Not that I'm the least bit xenophobic, but is there an exodus of UK architects to Poland?'
The ARB was unavailable for comment.