You can fix this by adding a UK date format switch to the merge field, eg:
{MERGEFIELD AccessDate \@ "dddd, d MMMM yyyy"}, or
{MERGEFIELD AccessDate \@ ", d MMMM yyyy"}, or
{MERGEFIELD AccessDate \@ "d MMM yyyy"}, or
{MERGEFIELD AccessDate \@ "dd/MMM/yyyy"}, or
{MERGEFIELD AccessDate \@ "d-MM-yy"}
etc