The rennovators say they merely want to make a few small changes to make the place more suitable for modern worship but are otherwise leaving the high altar, most of the altar rails, the tabernacle, etc.
The rennovators have published this list of myths and facts. But the Friends of St. Colman's Cathedral have a far more impressive apparatus. Take a look at their site. This isn't merely reactionary reflexes at work here.
This BBC story, for example, notes that "the original plans for change involved removing marble altar rails, and lifting up mosaic flooring"--all for the purpose of giving "people a better experience of the celebration of worship," don't you know.
For now, the plans for rennovating the interior have been stopped by a local planning board, even as the Bishops involved are decrying the intervention by the state in matters that belong to the Church.
Here is a remarkable picture of the interior as it presently stands
