The European Commission will this week hand Hutchison its list of formal objections over the deal, including concerns that the merger will lead to price hikes for consumers.
But Canning Fok, chairman of Three and managing director of Hutchison, has promised the merged operator will not raise its prices across voice, text or data services for five years after the deal goes through. "Like for like, customers’ bills will go down," he said.
Fok also pledged that the merged operator would invest £5bn in its network to improve capacity, coverage and data speeds – more than either company would invest separately.
Lastly, the brand will offer up some of its own network to rivals, something Fok described as "unprecedented" in the UK.
"It eliminates the tricks some wholesalers use to disadvantage their wholesale customers and thus make it harder for them, in turn, to make competitive offerings to their own customers," said Fok. "This approach will deliver real competition, not just slogans."
Fok also poured scorn on comments made this week by Ofcom’s chief executive, Sharon White, who noted a merged Three and O2 would leave the UK with just three mobile networks.
Writing in the Financial Times, White said: "[We] are concerned that the smallest mobile network, Three, proposes to become the biggest by acquiring its rival, O2. The combined group would control more than four in 10 mobile connections."
Fok slammed White for failing to take Hutchison’s views into account, and described Three as a "major competitive force" in the UK.
This week, BT completed its acquisition of the UK's biggest mobile operator, EE.