A 24-hour Tube strike is underway on the Bakerloo line after talks failed to resolve a row over staff safety.

About 150 members of the Rail, Maritime and Transport (RMT) union walked out at 10pm last night.

The union is protesting against a decision by London Underground (LU) to let one platform staff instead of two evacuate trains at stations north of Queen's Park.

If staff worked alone, they were more likely to be assaulted, the RMT claimed.

But LU said it was already "normal practice" to let one staff clear trains when a second person is unavailable. In such cases, the train driver helps them.

An "anomaly" on the northern part of the Bakerloo line meant procedure did not allow this practice, LU said.

"This anomaly has caused unnecessary delays, inconveniencing passengers and sometimes resulting in a loss of services.

"The change in procedure is to correct this anomaly. This strike action is completely unnecessary and will not achieve anything."

However, RMT general secretary Bob Crow said yesterday: "At talks earlier this week we reminded LU that having a minimum of two station staff on duty at stations where detraining takes place is essential, not least at stations with high crime levels, but the company has refused to budge.

"LU is still set on reducing standards of station staffing, which will expose more of our members to the risk of assault, and the strike will now go ahead."