The "unfavourable trade deal" would be of the kind that could command more support in Parliament, i.e. was more favourable to HMG's position (presumably with th

The "unfavourable trade deal" would be of the kind that could command more support in Parliament, i.e. was more favourable to HMG's position (presumably with the Irish backstop removed, for one). By definition that would mean the EU giving more in the negotiation, i.e. it would be less favourable to them.