The energy supplier says it will increase its standard variable gas and electricity prices in October. : The company said the rise was due to wholesale energy costs having risen by more than 20% since April. It is the second price increase announced by Scottish Power this year. In April, it said it would raise its gas and electricity prices by 5.5% for a third of its customers from 1 June. On Friday, Neil Clitheroe, chief executive of Scottish Power's retail division, said the increase in standard variable prices reflected "rising wholesale energy costs and compulsory non-energy costs".