The £2m push, created by Feel Agency, with media planning and buying by Total Media, kicks off on Monday with a competition to find the UK's best home-cooked vegetarian dish.
The competition will be promoted on-pack and via a social media campaign, as well as through point-of-sale activity. The winning recipe will be taken up by the brand to become part of the Linda McCartney range.
The TV ads will air in the spring during This Morning on ITV, and will be the only commercials shown during the programme for an entire week.
Each ad will include a mini-documentary featuring one of the three finalists. The winner, who will be decided by a public vote, will be announced in April; the winning dish will go on sale in September.
The Linda McCartney brand was a pioneer in the mainstream meat-free category. Since Hain acquired the brand from Heinz in 2007, it has extended its range and distribution in a drive to appeal to a broader audience.
Recent additions to the range include Mozzarella 1/4lb Burgers, launched last month, and Vegetarian Chilli with Wedges.