MAY WARNS RUSSIA

Colonel Sergei Skripal was released by Russia in a prisoner swap in 2010

LONDON : Prime Minister May warns of action if Russian role in nerve attack is proved.

''The use of nerve agent on UK soil is a brazen and reckless act. This was attempted murder in the  most cruel and public way,'' said interior minister Amber Rudd to the parliament in a statement.

Britain will respond appropriately if evidence shows Moscow sponsored a nerve agent  attack  on a  Russian ex-spy and his daughter in southern England, Prime Minister Theresa May said on Thursday, in the highest-level warning of action  action to date.

Former  double agent  Sergei Skripal, 66, and his daughter Yulia, 33 have been in hospital since they were found unconscious on Sunday on a bench outside a shopping centre in the quiet cathedral city of  Salisbury.

British media  and some politicians have speculated that the  Russian state could be  behind the attack    -suggestions dismissed by Moscow as knee-jerk, anti-Russian propaganda.

''We will do what  is  appropriate, we will do what is right, if it is proved to be the case that this is  state-sponsored,'' May told ITV News, when asked whether  Britain could expel the  Russian Ambassador over the attack.

''But let's give the  police the time and space  to actually conduct their investigation,'' she added, in her first comments on attack since police said on Wednesday a nerve agent was used.

''Of course, if action needs to be taken then the government will do that. We'll do that properly, at the right time, and on the basis of the best evidence,'' she said.

Scientific tests by government experts have identified the specific substance used, which will help identify the source, but authorities have refused to disclose the details.