Two teachers have been banned from the classroom for life, as the General Teaching Council for England handed down its toughest sanction for the first time since 2007.
Stephen Carr, who taught at a Newcastle school that cannot be named, had an "inappropriate relationship" with a pupil, sending her texts and going with her on holiday.
Frank Aboagye, who taught most recently at Sir Frank Markham School in Milton Keynes, was found to have an attitude problem and to have persistently lied to his school.
The unrelated cases take the total to just seven teachers struck off for life since the council was set up in 2001. The last one was in September 2007, after a teacher had started a sexual relationship with a pupil.
Mr Carr's "inappropriate relationship" was with an A-level pupil.
In October 2005, after she told her parents she had been exchanging texts with her teacher, he met them and apologised, and said their relationship would cease.
But the following January a message from Mr Carr was found on the pupil's computer; in the February he sent her a Valentine's card.
In a further meeting with her parents, he apologised again and said he would resign and move away from the area. Mr Carr did resign, but while on sick leave during his notice period he went on holiday with the pupil to New Zealand.
In its ruling, the GTC said: "The committee considers this behaviour to be a most serious breach of the standards of propriety expected of registered teachers. Pupil A was doing well at school and she was expected to go to university. The breach of trust that led to this relationship disrupted her school experience and set back her life chances."
The professional conduct committee criticised Mr Carr's lack of insight and his unwillingness to accept responsibility for the relationship, saying he had "engaged in sustained deception". It judged there was a risk of the behaviour being repeated.
Mr Aboagye was found to have "displayed persistent dishonesty over a long period". The council said he had lied about his reasons for absence at a previous school and had been dishonest when he denied any of his former schools had raised concerns about his performance.
He also accepted a job at a school but did not resign from his previous post, meaning he was effectively employed by two schools at once, the council heard. And in May 2006 he called in sick to attend a conference in China as an employee of another company.
Mr Aboagye claimed he had been treated unfairly and was a victim of racial discrimination, but the council found no evidence of that. It ruled: "In our view, he has displayed attitudinal problems and no insight into the harmful consequences of his behaviour. We find his behaviour to be fundamentally incompatible with being a registered teacher."
TEACHER WHO USED CRACK BACK IN CLASS
A teacher who used crack cocaine and fell asleep in lessons and on a school trip to the zoo has been allowed to return to his job.
William Horseman, who now works at Merchants' Academy in Bristol, admitted being a crack user while teaching at The Ridings High School in Winterbourne, near the city.
The General Teaching Council for England found Mr Horseman guilty of unacceptable professional conduct, but allowed him to return to the classroom with a conditional registration order.
He must report to the council three times a year for the next two years, confirming that his conduct has been satisfactory.