Lord McAlpine, a former Tory treasurer and deputy chairman, will take legal action against "all media" who have defamed his reputation.
The planned legal action comes after he issued a public statement earlier today denying the "wholly false and seriously defamatory" claims against him.
The 70-year-old peer has been subject to a frenzy of online speculation that he was the senior Conservative from the Thatcher era involved in child abuse in care home around Wrexham, North Wales. Juliet Bremner reports:
Lord Mc Alpine warned in a statement that he had not given up his right to sue those who defamed him in the recent past, and said he was "entirely willing" to meet the police so they can eliminate him from their investigations.
He said "ill or misinformed commentators" had used the internet to identify him "as this guilty man" and accused the broadcast and print media of defaming him "by innuendo."
He issued a categorical denial of the allegations whispered against him:
This Morning presenter Ruth Langsford read out an apology from Phillip Schofield after he presented the Prime Minister with a list of alleged child abusers live on air yesterday.
Prime Minister David Cameron told ITV News earlier today it was important for proper evidence to be presented, before allegations were made: