Nick Clegg has stepped up his attack on "Slacker Johnson" by mocking the mayor of London's lack of activity over the past week.

Speaking on LBC Radio on Thursday morning, the deputy prime minister said of Boris: "Isn't he living up to his reputation? The only photos I've seen of him this week: him playing tennis at Queen's and prancing around at a fashion show."

"Talk about fulfilling my predictions that he'll be known as 'Slacker Johnson' from now on."

boris johnson
Boris 'prancing' around at a fashion show with some models

Clegg also raised the prospect of the pair having a showdown on the tennis court. "Maybe one day there'll be a match," he said, adding that it would be "foolhardy" to predict that he would beat his sparring partner.

Told that Boris plays with a wooden racquet, he said: "He is admirably old-fashioned, I guess. That's one thing to be said for him."

Clegg first levelled the "slacker" charge after it was announced the top Tory would also host a phone-in on the station, but only one a month.

SEE ALSO: Boris Playing Tennis Is The Most Ridiculous Thing You'll See All Week (PICTURES)

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  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Michael McIntyre takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Michael McIntyre takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    (left to right) Boris Johnson, Jonathan Ross, Jimmy Carr, Andy Murray, Ross Hutchins, Tim Henman, Richard Branson, Eddie Redmayne, and Michael McIntyre take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Eddie Redmayne (right) and Tim Henman (left) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    London Mayor Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Ross Hutchins (left) and Andy Murray (right) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Michael McIntyre takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Ross Hutchins takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    London Mayor Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Jimmy Carr takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Eddie Redmayne (left) and Tim Henman (right) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    London Mayor Boris Johnson (centre) takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Richard Branson takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Jonathan Ross is helped up as he takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Boris Johnson, Richard Branson, Michael McIntyre

    Mayor of London Boris Johnson, left, chairman of Virgin Group Richard Branson, center, and comedian Michael McIntyre wait for their turn to play in a Rally Against Cancer charity tennis match at the Queen's Club grass court championships in London, Sunday, June 16, 2013. (AP Photo/Sang Tan)

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    London Mayor Boris Johnson takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Jimmy Carr takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Jonathan Ross (right) and Andy Murray (left) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Richard Branson takes part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Boris Johnson

    Mayor of London Boris Johnson in action as he plays in a Rally Against Cancer charity tennis match at the Queen's Club grass court championships in London, Sunday, June 16, 2013. Johnson played with chairman of Virgin Group Richard Branson. (AP Photo/Sang Tan)

  • Boris Johnson, Richard Branson

    Mayor of London Boris Johnson, left, and chairman of Virgin Group Richard Branson, react as they wait for their turn to play in a Rally Against Cancer charity tennis match event at the Queen's Club grass court championships in London, Sunday, June 16, 2013. (AP Photo/Sang Tan)

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Marin Cilic during his match against Andy Murray in the final of the AEGON Championships at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Marin Cilic during his match against Andy Murray in the final of the AEGON Championships at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Eddie Redmayne (left) and Tim Henman (right) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    Eddie Redmayne (right) and Tim Henman (left) take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

  • Tennis - AEGON Championships 2013 - Day Seven - The Queen's Club

    (left to right) Boris Johnson, Jonathan Ross, Jimmy Carr, Andy Murray, Ross Hutchins, Tim Henman, Richard Branson, Eddie Redmayne, and Michael McIntyre take part in a celebrity tennis match in aid of the Royal Marsden Hospital at The Queen's Club, London.

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