News that Watson was planning to stand down broke yesterday. He is yet to comment publicly.
Watson has been overseeing the Government's response to the recent public administration select committee report calling for greater transparency in lobbying.
The Cabinet Office has still not published its verdict - even though it had originally intended to respond to the select committee by 5 March.
The respected lobbyist and former president of the CIPR Lionel Zetter said today: ‘In theory, anybody new coming in would have some kind of say about the response if it's not already formed. It could now be delayed by a week or a month or until the eve of the summer recess, but it won't go away.'
Bell Pottinger Public Affairs chair Peter Bingle was more sceptical. He said: ‘Tom's departure means that in the short-term there is no momentum within HMG to do anything about lobbying. The focus now needs to be on the Tories.'
And Open Road CEO Graham McMillan suggested that ministers would be wary of cracking down on lobbyists in the current climate as it could look like a 'diversionary tactic'.
Meanwhile, campaigners for greater transparency were hopeful that Watson's replacement would act more quickly on the issue.
SpinWatch spokeswoman Tamasin Cave said: ‘Tom Watson has dithered for five months over the select committee's recommendation for a mandatory register of lobbyists. Let's hope his successor is serious about it.'