[1] At the 1727 British general election Holmes was returned as a Tory Member of Parliament for Newtown, where his family shared the electoral influence with the Worsleys.
It was accepted that he should have first use of the seats for himself and his family and at the 1747 general election, he was returned unopposed with his brother Henry, for Yarmouth.
[1] He did not have as much power as many borough-owners who could directly return MPs, but he exercised his influence in favour of government candidates.
[2] Holmes was sufficiently valuable to the ministries of Pelham and Newcastle that he was able to ask for and receive secret service payments for each seat he secured.
His only son by his first marriage predeceased him and the peerage became extinct on his death, but was revived in 1797 in favour of his nephew Leonard Holmes.