By Guy Taylor The Bakerloo Line could suffer a “critical failure” if the government does not provide funding for a planned upgrade and extension, London’s business scene and a slew of local authorities have warned. A report by Central London Forward, a partnership of 12 central London Boroughs, warned of the “escalating risks of inaction” to replace the Bakerloo Line’s rolling stock, which is the oldest still in passenger service in the UK. Built in 1972, the trains are now 16 years beyond their intended lifespan, while maintenance costs are higher than other lines and rising. The failure rate…