Mobile broadband provider 3 has continued its recent criticism of the proposed merger between rival firms T-Mobile and Orange.
Kevin Russell, Chief Executive of 3 UK, said the European Commission-approved deal raises key competition and consumer issues, given that it will reduce the market from five to four providers.
"These include the imbalance of radio spectrum holdings, penal mobile termination rates and a failed mobile number porting system," he commented.
Mr Russell said it is key that the Digital Britain proposals are passed to begin to address the radio spectrum issues.
In addition, he claimed that media regulator Ofcom must act on mobile termination rates and mobile number portability "if it is serious about the UK being a competitive market with true consumer choice".
"The need for action to address competition issues in the UK has never been greater," Mr Russell stated.
Last month, 3 UK's Chief Executive said the Office of Fair Trading must scrutinise any potential deal between T-Mobile and Orange, irrespective of the stance taken by European lawmakers.