Celebrity gardener Diarmuid Gavin has been brought in to help judge UK architecture鈥檚 most prestigious prize after two of its five original judges resigned from the jury.

Gavin, presenter of the BBC鈥檚 Gardeners鈥 World and a contestant on Strictly Come Dancing in 2004, was drafted in to be this year鈥檚 celebrity judge for the Stirling prize after the first choice, fellow BBC presenter Lauren Laverne, pulled out.

In: Gardeners鈥 World鈥檚 Diarmuid Gavin has been signed up to the jury
In: Gardeners鈥 World鈥檚 Diarmuid Gavin has been signed up to the jury

Ben van Berkel, an architect at Dutch practice UN Studio, has also resigned from the jury, to be replaced by Czech architect and former Cabe commissioner Eva Jiricna.

Both Laverne, who presents the BBC鈥檚 Culture Show, and van Berkel blamed lack of time for their withdrawal.

Sources close to the judges said the RIBA had been trying frantically to replace the pair for about a fortnight.

The Stirling prize will be awarded at a ceremony in Liverpool on 11 October, and televised on Channel 4 the night after.

Out: The Culture Show鈥檚 Lauren Laverne blamed lack of time for her withdrawal
Out: The Culture Show鈥檚 Lauren Laverne blamed lack of time for her withdrawal

The other judges are Gordon Murray of Murray Dunlop Architects, Shelley McNamara of Grafton Architects and Kieran Long, editor of the Architects Journal.

Clashes with schedules can arise, and are just something that has to be dealt with

Riba spokesperson

All five judges must visit the six shortlisted buildings during the six-week period before the prize is awarded.

Previous celebrity Stirling judges have included Stella McCartney in 1999, Joan Bakewell in 2005 and Mariella Frostrup in 2006.

An RIBA spokesperson said: 鈥淎lthough every effort is made to ensure the judges鈥 availability well in advance of the site visits, clashes with schedules and other extenuating circumstances can arise, and are just something that has to be dealt with.鈥

The architects nominated for this year鈥檚 Stirling prize are Allford Hall Monaghan Morris, Allies and Morrison, Denton Corker Marshall, Grimshaw/Arcadis, Feilden Clegg Bradley/Alison Brooks Architects/Maccreanor Lavington, and Zaha Hadid.