A Labour MP has insisted he will not be intimidated after an "absurd" complaint was made about him to party officials by Jeremy Corbyn's office.
Neil Coyle wrote to the leader to raise concerns over the lack of briefings for MPs on Brexit and growing criticism of Labour's slow response in reacting to major news stories.
But he was then reported for "not raising questions with the line manager" to chief whip Nick Brown and general secretary Iain McNicol by office manager Karie Murphy.
The Bermondsey and Old Southwark MP said the "insinuation" was that he had been "having a go at party staff", but he accused Mr Corbyn's aides of trying to shut down critics.
He told the Press Association: "I think it is an absurd situation and I think it is very frustrating that questions my members ask will not be answered by the man responsible.
"Rather than address the issues I have raised, the knee-jerk reaction is to make accusations about me, make a complaint about me.
"I won't be intimidated. They're shouting down anyone who dares to raise the tiniest of concerns about losing Copeland or being 20 points behind the Tories in the polls.
"There were two sets of concerns about communications issues and I just asked about how things would be improved and what had happened.
"Instead of getting answers or even an explanation of what had happened, I got a reply from the executive director, saying that she had reported the email as a formal complaint to the chief whip and general secretary of the party.
"That was a private email clearly from me to the leader of the party.
"I was so shocked at the reply. What's very frustrating is that this comes on top of other problems like questions at PLP and parliamentary committee just not being answered.
"This is another means of some who surround Jeremy trying to prevent him having to answer any questions."
Mr Coyle, a long-standing critic of Mr Corbyn, said the leader's office had previously ignored his attempts to ask questions.
"There was a period where emails to Jeremy's office didn't get answered at all, so getting a reply was a step up I thought, until I opened it," he said.
It comes after recent polling found just 45% of Labour supporters backed Mr Corbyn as the best prime minister for the country in a head-to-head choice between him and Theresa May, dropping to 14% among all voters.
Mr Coyle said there was "no effort" to address the challenges the party is facing.
"There's a lot of damage being done by the Tories," he added. "We should be winning. We should be communicating better what the Tories are doing, the damage it is doing to everyone."