Thames swimming columnist Matthew Parris criticised
The Port of London Authority has criticised a newspaper columnist who swam across the River Thames.
Former Tory politician Matthew Parris wrote in his Saturday Times column that he had swum across the river in central London in his vest and trunks.
"Frankly swimming in the Thames is not only ignorant it is selfish too," said David Snelson, Port of London Authority chief harbour master.
"It was ignorant and it was dangerous," Mr Parris admitted in his column.
"It could have ended in disaster," he added, admitting that he was "no great swimmer".
Mr Parris attempted to swim from the Globe Wharf apartment complex, in Rotherhithe, south-east London, across the river to Narrow Street, in Limehouse, north-east London.
The 60-year-old had planned to swim across the river at high tide to reduce the risk of being swept upstream
However, he had not realised that navigational tables were in Greenwich Mean Time (GMT).
As it was British Summer Time (BST) when he made the swimming attempt, high tide was an hour later than he had expected.
Consequently he was swept three-quarters of a mile upriver from Limehouse.
The Port of London Authority's Mr Snelson said the Thames in London was "lethal".
"It is important to emphasise that the dangers of swimming are not simply that the swimmer will drown," he said.
"A boat or larger vessel coming across a swimmer in the river might have to swerve to avoid him and risk collision with another vessel or bridge or pier.
"Some Thames passenger boats carry hundreds of passengers."
Mr Parris said he had no comment to make about the Port of London Authority's criticism.