This is an operational matter for Network Rail. I understand, however, that they are working with London Underground to ensure that passengers are re-directed to the most appropriate alternative route until the works are completed at the end of this month.
Any work carried out at stations must comply with the standards in “Train and Station Services for Disabled People: A Code of Practice (2002)”. The Department would only expect to be consulted if proposed works did not meet these standards. Network Rail also has a duty under part 3 of the DDA 1995 to make reasonable adjustments to allow access to their goods and services. They are responding to this duty.
As a condition of their licence to operate, Network Rail are required to publish a Disabled Persons’ Protection Policy, approved by the department, setting out the service level they commit to provide to people with reduced mobility, when accessing their stations.