The on air number for PrimeTime Radio is 0870 950 6061.  I have discovered that when I called the office number (which is an 0207 number, calling the other number I was answered by another person operating a swithboard in reception, not the presenter.

I asked what did it say onthe screen and was told it said "C05".  I had no idea what that meant, but he told me that he did not know which number I had called to get through.  I cannot confirm it, but is there really a different geographic number for the studio rather than the reception area?  The reception number is 0207 828 1954.  They continue to insist that there is no geographic equivalent number for the studio!  Thanks.

As it happens I have just looked at the PrimeTime website, and the 0870 number I mentioned is the Reception number - ie the same as the geographic number I already know.   Therefore I shall add it to the list.