Health Education England (HEE) chief executive Professor Ian Cumming told MPs this year's third round of recruitment for GP training posts had seen 676 people apply so far, compared to around 100 in 2014.
Describing the recent 'nothing general about general practice' marketing campaign - launched to coincide with the recruitment round - as 'controversial' among some, Professor Cumming said: 'We have seen 676 people apply for round three training.
'Whether or not there is a direct link, we don't know yet.' But he added that the increase was 'very, very significant'.
Professor Cumming told MPs that despite perceptions there had not been a decrease in GP trainees in recent years. Rather, applications had flatlined while training places had increased, leading to a falling fill rate. Also, he added, some regions had seen falling trainee numbers as doctors moved to fill increased places in London and south-east England.
One in five GP trainee posts were vacant after two rounds of recruitment this year. And in 2014, 12% of places went unfilled. Just 72 out of 451 vacant training places were filled when HEE opened an unprecendented third recruitment round last year.
The #nothinggeneral campaign attracted criticism from some GPs on social media when the first video focused on a GP signing a consent form for a cancer patient who wanted to skydive. Subsequent films have featured child mental health, sports injuries, and asthma.