Order in which \mark and \tempo are stacked above a staff

[Richard Shann]

Hi,
I was wondering what influences the order in which things like \mark and
\tempo are stacked above the staff.
In the following LilyPond the fermata appears above the tempo when
typeset (v. 2.16.0)

\new Staff {
\time 2/4 fis' g'4 
         \time 4/4 \tempo "a tempo" \mark \markup { \musicglyph
#"scripts.ufermata" } d'16 b' d'' b' d' b' d'' b' e' b' e'' b' e' b' e''
b'
        
}

I have tried reversing the order in which they appear in the lilypond
but that has no effect.

Any ideas how to get the fermata directly over the barline?

Richard Shann