The Queen is likely to decide on the day whether she will make appearances at her Platinum Jubilee celebrations next month.
The 96-year-old monarch has been suffering from mobility issues recently that have forced her to pull out of several key engagements.
Over the course of the Jubilee weekend, she is expected to appear at Trooping the Colour on the Thursday, a church service at St Pauls's Cathedral on the Friday and at the Epsom Derby on the Friday.