Three former cabinet secretaries have condemned the attacks on the right-hand man of Prime Minister Olly Robins, the main public official in negotiations to leave the EU.
Lord Armstrong of Ilminster told The Times that "those who wish to undermine or frustrate" Mrs. May's policy on Brexit should "concentrate their fire on the organ grinder" rather than on the "monkey".
His call was backed by Lord Butler of Brockwell, who said that such attacks were not in the national interest, while Lord O & # 39; Donnell said that "attacking our own officials" would not help the United Kingdom at the negotiating table.
Earlier this week, interim Cabinet Secretary Sir Mark Sedwill wrote to the newspaper to defend Robbins, who, critics say, wants to keep the United Kingdom in close orbit to the EU.
In a 35-minute conference call with around 130 company leaders, Theresa May tried to address concerns about the progress of the Brexit talks.
It is said that Mrs. May told them that she is confident that an agreement can be reached, even though time is not on her side.
Speaking to the BBC Radio 4 PM program, Stephen Martin, CEO of IoD, said the prime minister did not say that the extension of the transition period is being considered.
Martin said: "She fully accepts that time is running out and that a deal must be made in the fall, as she said."
"We need time to prepare for that, it was very clear and accepts the uncertainty that is causing the moment and the impact it could have."
"But I was making it clear to everyone that she believes a deal can be made and that she is safe.
"The only point of conflict is the Northern Ireland border and the support agreements."
A spokesperson for Downing Street said that Ms. May acknowledged that there were "some important problems" that were pending, but said the leaders had the feeling that they were willing to reach an agreement as soon as possible.
It came after the Japanese auto firms expressed concern about a Brexit without an agreement that, they insist, must be "avoided at all costs."
Akio Toyoda, president of the Automobile Manufacturers Association of Japan, said the group expects the UK and EU governments to "continue to make every effort to reach a satisfactory agreement."
At the summit of the European Council in Brussels this week, the EU chiefs suggested the 21-month transition period for the UK to leave the EU after the formal Brexit date of March 29, 2019.
But Ms. May's suggestion that she would be willing to delay leaving the country until 2021 to reach an agreement on the Irish border was met with the reaction of members of her own party.