Since City Hall opened in 2002 members of the public have been able to visit the building and enjoy the view from the top floor during one weekend each month. Now budget cuts could spell the end of this public access.
In response to a question from Labour London Assembly Member Joanne McCartney asking him to reconsider plans to end the weekend open days, the Mayor conspicuously failed to rule out cutting the funding for weekend public access.
"I have not yet confirmed that most weekend openings of City Hall to the general public will cease in the new financial year," replied Boris Johnson. "This would be subject to a decision taken in line with the authority's decision-making framework."
The Mayor disclosed that the Greater London Authority currently spends £44,000 a year on the weekend openings which attract an average of 850 people, putting the cost to the taxpayer for each weekend visitor at more than £4.50.
"I know how much Londoners as well as tourists relish the chance to take a closer look at the GLA (including the walk down the spiral staircase and the view from the 9th floor) and I believe we should not miss the opportunity to bring City Hall closer to the people," said Joanne McCartney, who also asked the Mayor to consider better promotion of the open days or offering late-evening public access instead.
Parts of City Hall are open to the public from Monday to Friday, but weekday visitors can't usually gain access to the top floor space known as 'London's Living Room' and the balcony or the spiral staircase and ramp.
The disclosure of the possible reduction in public access follows Boris Johnson's admission last month that he is less enamoured of the architecture of City Hall than Ms McCartney.
Addressing guests at the London Planning Awards the Mayor said that Norman Foster-designed City Hall has "windows which do not open but are almost impossible to see through because they are constantly covered with guano or other substances and are impossible to clean.
"And whoever knows the secret of cleaning the windows in City Hall has either died or crept away to South America and there's nothing we can do about it."
Speaking in the Chamber at City Hall, he added: "Above me you can see is a staircase that is almost entirely unused but nonetheless occupies most of the volume."
City Hall forms part of the More London estate which won the 'best built project' category at the London Planning Awards. The citation described it as "a catalyst for the transformation of North Southwark".
Just days after the Mayor presented the award to More London, it emerged that the GLA's own landlord has defaulted on a $960 million loan.
Bloomberg reported last week that the terms of the loan were breached in January when the More London estate's value fell to £754 million; 21 per cent below a valuation in October 2006.