After 15 years at Above Bar Church, Jackman was recruited by Dick Lucas to found the Cornhill Training Course in London in 1991.

[2] The course is a ministry of The Proclamation Trust, and is designed to train evangelical preachers in exegesis, exposition and communication skills.

[6] His expository writing work includes commentaries on Judges & Ruth,[7] the Letters of John,[2] and Let’s Study 1 Corinthians.

[2] In addition to his role at The Proclamation Trust, Jackman is a visiting lecturer at Oak Hill Theological College in London as an expert in free church ministry.

[2] He is a former chairman of the 9:38 Committee, a national evangelical interdenominational organisation established to help people consider the possibilities of paid gospel ministry.