Businesses will raise their voices, making common cause with pro-European MPs, the Treasury (in the person of Philip Hammond, the chancellor of the exchequer) and a newly thrusting, liberal wing of the Tory party (led by George Osborne, his predecessor).
http://dictionary.cambridge.org/dictionary/english/thrust
As you can see it has meaning of "to push suddenly and strongly" Does it mean the liberal wings are violent or they are growing suddenly?