The by-election was held due to the disqualification of the incumbent Unionist MP, William Preston.

[1] The by-election was caused by the disqualification of the sitting Unionist MP, William Preston.

However, following his election, it was discovered that Preston had received payments for two small contracts to supply electrical fittings to the Post Office Stores Department.

As a government contractor, Preston was ineligible to stand for parliament, and his election was declared void.

On 21 February, although suffering illness, Lloyd George spoke at Walsall Town Hall in front of 2,500 people, in support of Macnamara.