Manchester United have officially canvassed season ticket holders to gauge support for safe standing.
In what is a significant step towards rail seats being introduced at Old Trafford, fans were asked whether they were for or against the idea.
United are advocates of proposals and travelled to Celtic Park in early October to examine the logistics of their 2,975-capacity standing section.
Premier League clubs are due for more discussions as to whether rail seats should be brought into stadia, with United keen to be on the front foot with their fanbase.