The panel - formed in 2005 on the coat-tails of Tony Blair's Better Public Building initiative - has responsibility for the design quality of the Home Office's building portfolio, including the UK's prisons, immigration centres and the police stations of 43 forces.
Johnson, who advised the Home Office on the panel's formation, added that she believed its future was 'undecided'.
The reason for the enforced hiatus is believed to be down to funding, however, the creation of a new Ministry of Justice department in June - which will control the UK's prisons - would also significantly reduce the panel's workload.
John Higgins, head of design policy at the Home Office, who founded the panel, refused to be drawn on the long term future of the panel, but said: 'At the moment we are responsible for all the buildings that have traditionally fallen under the Home Office. With the creation of the new ministry, we have not determined what the split will be.'
Higgins said it would be 'misplaced' to talk of the demise of the panel - which carries out around 15 reviews a year - and added 'there will always be projects that deserve our attention'.
A spokesperson from the Home Office said: 'The panel's work continues and the Home Office is optimistic it can maintain a level of work it has carried out in the past.
'We have been, and continue to look at alternative ways of funding this work.'