Blackpool chairman Karl Oyston has been charged by the Football Association for text messages in which he called a supporter "a retard".

Back in December it emerged that Oyston had sent a series of text messages to fan Stephen Smith, who he told to "enjoy the rest of your special needs day out".

Oyston later apologised for his part in the exchange, however the FA announced on Monday that the messages allegedly constituted five breaches of its rules and the Tangerines chief now has until 6pm on 30 March to respond to the charge.

A statement on the FA's website read: "Blackpool FC Chairman Karl Oyston has been charged by the FA in relation to comments made in a text message exchange.

"It is alleged that the misconduct constituted five breaches of FA rules, and that during the text message exchange, Mr Oyston used abusive and/or insulting words towards a supporter of Blackpool FC.

"It is further alleged that each of these five breaches of FA Rule E3(1) is an 'Aggravated Breach' as defined in Rule E3(2), as each included a reference to disability.

"Mr Oyston has until 6pm on March 30, 2015 to respond to the charge."

The content of the messages first emerged just before Christmas and Oyston came under fire from fans of his own club as well as anti-discrimination group Kick It Out, while the local paper the Blackpool Gazette scrapped his weekly column with immediate effect.

The Seasiders chairman issued an apology via the club's official website in which he explained he was responding to threats and abuse to his own family.

"I would like to unreservedly apologise for any offence or distress caused by my text responses reported in the media recently," he said.

"I regret stooping to the level of those threatening and abusing my family.

"My mobile number was placed on a social media website recently and it led to a barrage of abuse about my mother, father, wife, children and myself.

"In hindsight the aim of this was clear, and I foolishly opted to challenge some of the abuse, harassment and threats.

"Given my position, I should have acted with more responsibility and reported the abusive text messages, phone calls and answer phone messages to the police, rather than get embroiled in such an exchange."

However, Smith himself told Press Association at the time that he had not accepted Oyston's apology.

Smith also claimed Oyston's position at the helm of Blackpool had become "untenable".

"The apology is weak," he said.

"He has said that he is responding to messages that threatened and abused his family. I did not threaten or abuse any member of his family. His position as chairman is untenable. He has no choice but to resign."

Oyston has endured a frosty relationship with Blackpool supporters who have been disillusioned by events on and off the field during a tumultuous year at Bloomfield Road.

Last Saturday hundreds of fans protested against the Tangerines' ownership and opted to go and watch non-league AFC Blackpool instead, boycotting the fixture between Lee Clark's men and Leeds.

Blackpool are 17 points away from safety in the Sky Bet Championship and their relegation could be confirmed in their next game against Bolton.