Tube workers could go on strike after plans emerged last week to close all ticket offices on the London Underground.

The RMT transport union will hold a ballot today on industrial actions after 750 jobs were put at risk by the plans, which could save Transport for London more than £40m a year.

London Mayor Boris Johnson announced the cuts while revealing some tube lines, including the Northern Line Morden branch, would run for 24 hours on weekends from 2015.

The RMT's general secretary, Bob Crow, had indicated several days of strike action could be on the cards.

It is also due to meet with the TSSA transport union Ttoday to discuss a joint campaign.

Phil Hufton, London Underground's chief operating officer, insisted the proposals will not lead to compulstory redundancies and urged the unions to work with TfL on the plans "rather than threaten hard-working Londoners with completely unnecessary strike action".

Any strike action by the RMT union needs to have a two-week ballot of its members. Once the vote is held TfL must be give seven days' notice.

TfL's budget will be reduced by £78m in the financial years of 2013 and 2014.