At the 1708 British general election, he was returned as Member of Parliament for Inverness-shire on the family interest.
He was absent at the start of the Parliament as his regiment was ordered to join the continental army of the Duke of Marlborough.
In September 1709 he returned to the Continent to command his men at the Siege of Mons.
He was back in London by January 1710, and was listed as voting for the impeachment of Dr Sacheverell.
[1] Grant was returned again as MP for Elginshire at the 1715 British general election, and followed the Duke of Argyll in Parliament.
He was colonel of a new regiment of foot in 1715 and appointed governor and store-keeper for Sheerness, and acting lieutenant-governor for Edinburgh Castle.
He also became Lord Lieutenant of Banff, Elgin and Inverness in 1715 and was active in raising his clan in support of the Government, promising them ample compensation for any losses, which in fact did not materialize.