Coulson resigned as the paper's editor after royal reporter Clive Goodman was jailed a few months earlier for hacking into the phones of members of the royal family's household.
Former Home Secretary (interior minister) Charles Clarke said Conservative leader David Cameron, who leads in the polls with an election less than a year away, should sack Coulson.
Cameron said he would not get rid of Coulson, adding, "I believe in giving people a second chance."
Privacy watchdog, the Information Commissioner's Office, said it gave Taylor's lawyers evidence last year of News International reporters buying and selling personal information after the ICO received a court order.
"This included material that showed that 31 journalists working for The News of the World and The Sun had acquired people's personal information through 'blagging'," the Assistant Information Commissioner Mick Gorrill said in a statement.
"Blagging" is a form of deception where a person pretends to be someone else in an attempt to obtain information from sources such banks or telephone companies, the watchdog said.
Macpherson's publicist said in a statement, "Elle is obviously very concerned that her private telephone conversations and those of other people may have been intruded upon by reputable newspapers."
(Additional reporting by Tim Castle and Luke Baker; Editing by Louise Ireland)