On top of that.
I presume that they mean exemption from the Low Emission Zone charge. If so this is not a government matter but a local authority charge. As far as I am aware it is only London that charges so the proper target for the petition woukd be Boris.
I wonder who the 'Motohome Caravanners Club' are, I've never heard of them.
Honestly, a petition worded like that one is not going to cut it with
anyone. Exactly what are the 'emmission charges' referred to in the
petition? There is no such thing in law as a 'motorhome' so they can't
be exempted from anything.