Sales of the cards, which began after the successful launch of the Saturday draw, have slumped from a peak of more than pounds 44m to a low of pounds 15m in the first week of this month.
Although details have still to be hammered out, the campaign will probably introduce a variety of innovative games to attract new punters, and also give players the opportunity to compete for prizes in a televised show.
A clue to the new approach is shown by the success of Camelot's Pigs Might Fly scratchcard, started last summer, which offered relatively low prizes of pounds 10,000 but which gave a higher than normal chance of winning - one in four as against one in five.
Lower prizes but with a higher chance of success, involving "humorous" formats, are seen as the way forward. Christmas bonus cards have also proved popular.
A spokesman for Camelot yesterday confirmed it was considering new ideas for scratch cards but was cautious about committing itself to specific ideas. He said: "We are always looking at new and innovative marketing initiatives for both the National Lottery game and Instants. We will continue to consider new game ideas with more variety to broaden appeal."
He added: "The Instants brand still outsells the top three impulse brands in the country - Coca Cola, Walkers and KitKat - and 10 million people play regularly each week."
The company points out that in other countries such as the US, instant games have slumped after launches, before recovering to gain a larger slice of the market.
If a new television show is launched, it is likely to be offered to the BBC which has a contract to show the lottery draws until this autumn. Cards would have a separate panel to be scratched which would give the purchaser the chance to appear in the programme and win a variety of prizes.
Camelot claims that its advertising and marketing for scratchcards has produced a "halo effect" for the sector as a whole - boosting sales from pounds 43m to pounds 100m a year. Around half of the UK population are thought to play instants at some time, with one in ten playing on a weekly basis.
Company sources said the fall in sales was not a "disaster" but that it needed to maintain or increase them so that, overall, commercial targets could be reached.
One said: "We did predict the market would drop but we did not want it to fall any lower."
The fall in sales can be traced back to early last year when the main lottery game offered its first double-rollover jackpot. Other scratchcard operators are thought to have seen similar falls in sales.
Another option is for Camelot to eschew altogether one-off prizes and instead offer regular monthly payments, as is done already in other parts of Europe.Reuse content