Nadine Dorries later deleted the tweet
The politician faced a Twitter backlash after she used the phrase, a derogatory term used to refer to disabled people.
Her message, which has since been deleted, read: “Window lickin’ Twitter trolls out in force today!”
She later claimed she had no idea of what the phrase meant after being bombarded by angry messages online.
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One follower, Neil Scarrot, told her: “I’m a fan of yours but thats in bad taste for anyone with disabled children.”
Another Twitter user blasted: “Horrified by this! In a constant battle against hate speech, how do we stand a chance of change when elected members use such vile terms.”
And one person tweeted: “Disgusting use of derogatory language from anyone never mind a sitting MP @NadineDorries is disgraceful.”
Nadine Dorries caused outrage with the tweet
Charity Mencap branded the tweet “offensive” but welcomed the fact she had deleted it and called for MPs to avoid using offensive language.
Ms Dorries told Express.co.uk: “I was relating a comment I had heard in relation to trolls, I had no idea it had any association with disabled people.
“I would never associate with anyone that did use it in that context.
“I deleted it as soon as I was informed that in the urban dictionary it had that connotation.
“To me it seemed relevant to idiots sat all day in front of computer screens.”
The outspoken MP for Mid Bedfordshire has previously run into trouble for her choice of words.
In 2012 she launched a withering attack on her party’s leadership, branding David Cameron and George Osborne a pair of “arrogant posh boys”.
The novelist and ex-nurse caused huge controversy in the same year when she appeared on hit show I’m A Celebrity while still a serving MP.
She temporarily had the party whip withdrawn before eventually returning to the Tory fold.