The militant union behind the strikes that have crippled Southern Rail is using its £46 million war-chest to pay conductors £300 a week to stay off work, it has emerged.

As 300,000 commuters in the south of England prepare for another day of transport misery, RMT officials confirmed that the union is handing its 400 conductors a tax-free allowance of £60 a day to strike, equivalent to a gross annual salary of more than £18,000.

The figure equates to around half of the standard £35,000 wage earned by conductors, and helps shed light on how the union has managed to persuade staff to keep the industrial action going for nearly nine months.