He was generally supposed to favour the claim of the pretender; but he was afraid of embarking too far in his cause, and avoided violent measures in the discussion of the treaty, lest he should incur the resentment of the English parliament, and forfeit the estate he possessed in that kingdom.
Athol was more forward in his professions of attachment to the court of St.Germain's; but he had less ability, and his zeal was supposed to be inflamed by resentment against the ministry.

The debates upon the different articles of the treaty were carried on with great heat and vivacity, and many shrewd arguments were used against this scheme of incorporating the union.

One member affirmed, that it would furnish a handle to any aspiring prince to overthrow the liberties of all Britain; for if the parliament of Scotland could alter, or rather subvert its constitution, this circumstance might be a precedent for the parliament of Great Britain to assume the same power: that the representatives for Scotland would, from their poverty, depend upon those who possessed the means of corruption; and having expressed so little concern for the support of their own constitution, would pay very little regard to that of any other.

"What!" said the duke of Hamilton, "shall we in half an hour give up what our forefathers maintained with their lives and fortunes for many ages?
Are here none of the descendants of those worthy patriots who defended the liberty of their country against all invaders; who assisted the great king Robert Bruce to restore the constitution, and revenge the falsehood of England and the usurpation of Baliol?
Where are the Douglasses and Campbells?
Where are the peers, where are the barons, once the bulwark of the nation?
Shall we yield up the sovereignty and independency of our country, when we are commanded by those we represent to preserve the same, and assured of their assistance to support us ?" The duke of Athol protested against an incorporating union, as contrary to the honour, interest, fundamental laws, and constitution of the kingdom of Scotland, the birthright of the peers, the rights and privileges of the barons and boroughs, and to the claim of right, property, and liberty of the subjects.

To this protest nineteen peers and forty-six commoners adhered.