The Alliance was increased to 16 clubs for the 1991/92 season, with the election of Welsh National league (Wrexham Area) champions Brymbo and Mid Wales League runners-up Llansantffriad. This would be a significant campaign in the history of Welsh football, not only for the on-going legal battle between the FAW and the eight ‘exile' clubs, who played in English non-league football and were resisting overtures to join the League of Wales for the following season, but also for what was to become known as the “Billy Morris Affair”. Welshpool Town appeared to be heading comfortably towards the title, when it was discovered that one of their players, Billy Morris, was actually serving a seven year ban from the Staffordshire F.A.
The Lilywhites were deducted 66 points; three for each match Morris played in, and dropped to the bottom of the table in the process, replacing Brymbo, who appeared to have been doomed for that particular spot.
Welshpool's loss was Caersws's gain, as the inaugural runners-up went one step better to claim the championship, before joining the League of Wales the following term. Llansantffriad, playing in only their second season of senior football, edged out Porthmadog, defending champions Flint Town United and Conwy United for runners-up spot. Caersws claimed a double by retaining the Central Wales Challenge Cup, when they once again overcame Morda United in the final, but were unable to lift the Welsh Intermediate Cup when the Bluebirds surprisingly lost to Llangefni Town, after a replay, in the final.
Lex XI retained the League Cup, defeating Flint in the final, whilst Gresford Athletic made up for a disappointing league campaign by overcoming British Aerospace in the North East Wales Challenge Cup final. In the Welsh Cup, Caersws, Llansantffriad and Mostyn carried the league banner the furthest, before departing at the third round stage to Cemaes Bay, Kidderminster Harriers and Hereford United respectively