Midland energy supplier npower has launched a multi-million pound battle to win customers from giant rival British Gas.
The campaign - created by Moseley-based agency KLM - could see the Worcester business double its advertising and marketing spending to £20 million.
The campaign aims to provide stark - and hard-hitting -comparisons between the services and prices the two business offer.
Kevin Peake, head of customer marketing, said: "We aim to build the brand and show to customers that we can compete and win in this competitive market place."
He said the first stage of the national print and poster suggested nPower was winning customers from British Gas. Another phase promoted products and propositions in contrast to British Gas.
A number of other arms of the campaign are either under way or set to be launched.
The company last year spent £10 million on market-i ng and promoting the business.
Mr Peake said that figure may rise to up to £20 million this year, "depending on the marketplace."
He said part of the company's marketing aim was to promote npower's colour branding as "warm and red."
The aim was to contrast with the British Gas image -which he described as "cold and blue."
One advertisement is headed " 'whodunnit?' with a secondary line - "who's charging you over £100 more on your fuel bills?' "
Jo Whittaker a spokes-woman for British Gas, said: "Despite what the ad claims, British Gas is still considerably cheaper than npower for electricity."
She conceded, however, npower came in cheaper for gas, adding " I make the point to show that at first glance, ads don't always give consumers the whole story."
Owned by Centrica, Windsor-based British Gas has 11.7 million residential gas customers and nearly six million electricity customers.
Jon Derry, chairman of KLM said: "Comparative advertising is both a powerful and potentially controversial communication technique.
"It must always be handled with care, but we feel that, as a "challenger" brand in a price sensitive market, npower can showcase their value-proposition best by reference to their principal competitor."
In a separate move, KLM has also been appointed to redesign the energy bills for npower's gas and electricity customers following a competitive pitch.
Supplier npower has around six million domestic gas and electricity customers and employs up to 400 people at its Worcester HQ.
Last year KLM said string of business had helped it announce a big boost in profits. In the Autumn, the company celebrated a 28 per cent growth in gross profit to £2.85 million. ..SUPL: