The President, Mrs McAleese, telephoned Catherina McKiernan immediately after the race to congratulate her on the victory, which she said was "a fitting reward for the dedication and commitment you have shown over the years".
She added: "The people of Cavan and of Ulster, together with Irish people everywhere, will join in celebrating this significant occasion in your career."
The Taoiseach, Mr Ahern, said the win proved McKiernan's status as a world-class athlete and was "all the more remarkable given that it was only Catherina's second marathon". He said Ireland was proud of her achievements and he wished her continued success.
The Fine Gael leader, Mr John Bruton, congratulated her on a "tactically brilliant race", which he said "marks a crowning moment in her career, following her win in Berlin last September, where she set the fastest marathon debut time ever".
He added: "This is the first time an Irish athlete has won the London marathon and this marks long overdue recognition of Catherina's contribution to the renaissance in Irish women's athletics."
The Minister for Sport, Dr McDaid also conveyed his warmest congratulations on "her magnificent success".
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