The pair have been engaged in a bitter battle recently after the TV presenter reunited with Danny Cipriani - who also dated the glamour model - in February and was called a ''heffer'' by her rival.
Now she has hit back on Twitter, slamming Katie for her claims the rugby hunk would be unfaithful and reports she was planning a ''kiss and tell'' of her time with the star.
Kelly since deleted her tweets, but wrote: ''MissKatiePrice Your doing a Kiss&Tell on Danny??
''Haha that's hilarious you dated for 5mins and was one of many at that time. Desperate.
''MissKatiePrice I saw the texts you sent him threatening me. So yes I've seen the messages. Will happily call you. DM me. (sic)''
On Tuesday night (28.05.13) the glamour model took to her own Twitter account to take aim at Kelly with claims Danny was still trying to contact her.
She wrote: ''IAMKELLYBROOK pick up the phone if you hav a prob instead of hiding behind a tv screen to bully me!
''IAMKELLYBROOK ask danny about his emails & texes sent to me behind your back which ill show you kieran agrees he will never be faithful (sic).''
Her comments followed Kelly mocking Katie's third marriage to Kieran Hayler on 'Celebrity Juice' when Keith Lemon asked the panel: ''What did Katie Price do for her husband on their wedding day?''
Kelly responded: ''Did she burn my calendar hanging on his wall?''
She then implied she was in touch with Danny when he was dating Katie in October 2011.
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