A key security adviser had no role in the "substance or the evidence" of the collapsed case against two men accused of spying for China, the education secretary has said.
The Conservatives have suggested Jonathan Powell, the prime minister's national security adviser, had a role in not giving prosecutors evidence they said they needed to secure convictions.
Charges against Christopher Cash and Christopher Berry – who both deny the allegations – were dropped last month, prompting criticism from ministers and MPs.
Asked about Mr Powell's involvement, Bridget Phillipson told the BBC: "I can give you that reassurance, he did not have those conversations around the substance or the evidence of the case."
Phillipson said ministers were "deeply disappointed that the case hasn't proceeded" and insisted the Crown Prosecution Service was "best placed to explain why it was not able to bring forward a prosecution".
