"The RMT, which opposed the privatisation of Tube maintenance, says track inspections have been reduced, threatening the safety of staff and passengers.
Union members met Tube managers at an emergency session of the London Assembly's transport committee on Thursday.
But although London Underground (LU) managing director Tim O'Toole (top name) told the committee safety procedures would have to be changed, the unions were not satisfied.
Speaking after the meeting Pat Sikorski, from the RMT, told BBC London: "We didn't get any assurances today that we would return to 24-hour inspections of every foot of LU track."
Lynne Featherstone who is chair of the London Assembly Transport Policy Committee was at these emergency talks and yesterday I emailed her (see below) to see if she would be prepared to comment on this blog. She emailed back to say yes, so let's hope she manages to reply.
Please continue to add your comments to the comments box for yesterday, so that she can see and hopefully address your views. Many thanks to everyone who has added comments so far, I really appreciate it.
When you see a picture of the carriage that hit the wall in the derailment at Camden it's amazing and incredibly lucky that more than seven people weren't injured. Something simply has to be done and I'm totally behind the industrial action to draw more attention, action and funding to this issue.
For more on the possible industrial action check out the various reports in Google News.