The security minister Ben Wallace has said that the Russian president Vladimir Putin is “ultimately responsible” for the deadly Salisbury nerve agent attack as a result of his firm grip on the Russian state.

His remarks are the furthest the British government has gone yet in attributing direct blame on Putin for the attempt by two Russian military intelligence officers to murder Sergei and Yulia Skripal with the military grade nerve agent in March.

Britain will seek to intensify diplomatic pressure on the Kremlin by laying out the case against Moscow at the United Nations security council, of which Russia is a member, on Thursday.

Theresa May did not explicitly blame Putin for authorising the attempted assassination, which resulted in the death of a British woman, when she addressed the Commons in a special statement on Monday, although she pointed the finger at the Kremlin.

Wallace told BBC Radio 4, however, that it was clear Putin held responsibility. He said: “Ultimately he does, in so far as he is the president of the Russian Federation and it is his government which controls funds and directs the military intelligence, the GRU, via his ministry of defence. I don’t think anyone can ever say that Mr Putin isn’t in control of his state.”

He added: “The GRU is without doubt not rogue. It is led, linked to both the senior members of the Russian general staff and the defence minister and, through that, to the Kremlin and the president’s office. Of course he’s responsible, he’s leader of the state.”