In 2009, Elmbridge Borough Council approved plans by Network Rail and developer Gladedale to redevelop the neighbouring train station and build 66 homes, a hotel, care home and retail and commercial units on the bank of the Thames opposite the palace.
Garner, a consultant to Historic Royal Palaces and Royal Botanic Gardens Kew, challenged the decision saying the work would damage a site of historic significance, but the development has now been given the go-ahead.
"This is going to cause irreparable damage to a national heritage site with international importance," said Garner. "The development will be more or less in front of the palace, so the view across open meadow as it is now will be totally blocked and visitors will instead be greeted by the back of the hotel."
Garner said he would consider appealing against the decision if he could obtain further funding.