Allen did not contest St Albans because he was selected instead to stand as Liberal candidate at a by-election in Leicester East in March 1922.

The election was caused by the appointment of the Coalition Liberal Member of Parliament Sir Gordon Hewart as Lord Chief Justice of England.

In a straight fight with the Conservative Party he narrowly missed being elected, the majority of his opponent, William Reynolds, being only 109 (or 0.4% of the vote).

This had the effect of splitting the anti-Tory vote and Allen fell to the bottom of the poll, the Tory Charles Waterhouse re-gaining the seat for his party.

[11] Allen tried to re-enter the House of Commons at the 1929 general election but he had switched seats and now contested the Banbury or North Division of Oxfordshire.

In a three-cornered contest he put in a strong showing, cutting the Unionist majority from 6,228 to 2,644 with Labour in third place but he could not remove the sitting Tory MP A J Edmondson.