The 1900 Portsmouth by-election was a parliamentary by-election held on 3 May 1900 for one of the two seats in the British House of Commons constituency of Portsmouth in Hampshire.
Vacancy.
The seat had become vacant when the Liberal Member of Parliament (MP) Walter Clough had resigned his seat on 23 April 1900 by the technical device of accepting appointment as Steward of the Manor of Northstead, a notional "office of profit under The Crown". The writ for the by-election was moved in the Commons three days later, on 26 April.
Previous result.
Electorate 24,057
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
! style="text-align:right;" | Swing
! style="text-align:right;" | Swing
Candidates.
The Liberal Party selected Thomas Bramsdon, a 43-year-old solicitor and a native of Portsmouth. The Conservative Party selected 29-year-old James Majendie.
Result.
The result was a narrow victory for Bramsdon. 
Electorate 26,698
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
! style="text-align:right;" | Swing
However, he held the seat only briefly; at the general election in October 1900, he lost his seat to Majendie.
References.
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