Sharp divisions have emerged within the European Commission about a plan to intensify competition in the region’s telecommunications market by splitting up big companies such as Deutsche Telekom and Spain’s Telefónica.

Neelie Kroes, European Union competition chief, and Günter Verheugen, the industry commissioner, have attacked a proposed overhaul by fellow commissioner Viviane Reding of laws to govern the bloc’s €289bn-a-year ($407bn) electronic communications sector.