Kirkman continued as BRA Eighth Army until 19 February 1943 when, as part of a new policy to transfer experienced personnel from the Eighth Army to the 18th Army Group, commanded by General Sir Harold Alexander. He was not there long, however, as, upon Montgomery's recommendation he was promoted to the acting rank of major general on 14 April 1943, and appointed as General Officer Commanding (GOC) of the 50th (Northumbrian) Infantry Division, succeeding Major General John Nichols, who had lost Montgomery's confidence following the Mareth Line offensive. The division − understrength with only two infantry brigades (69th and 151st) instead of the usual three − was a first line TA formation with extensive experience and was then engaged in the final stages of the Tunisian Campaign, serving in the Eighth Army's X Corps, then commanded by Lieutenant General Brian Horrocks, who had one of Kirkman's fellow students at the Staff College in the early 1930s.