Julian was first elected as MP for Skipton and Ripon on 6 May 2010, with a majority of 9,950 votes.

After being re-elected in 2015, Julian joined the Government in the Whips Office, serving as Vice Chamberlain of HM Household from July 2016-June 2017.

In June 2017, Julian was elected as the Member of Parliament for Skipton and Ripon with a majority of 19,985.

Julian was then promoted to Deputy Chief Whip, a position he held until being appointed Government Chief Whip in November 2017. Julian served in this role for just under 2 years.

Julian is currently the Secretary of State for Northern Ireland, being appointed to the role in July 2019 by the new Prime Minister, Boris Johnson.

Julian is not currently an MP, as Parliament has been dissolved until after the General Election.