The pace of reform within the European Union quickened yesterday with the announcement of plans for a team of "super commissioners" in Brussels.

Before the Seville summit of EU leaders on Friday, the European Commission president, Romano Prodi, has called for a fundamental shake-up of his existing college of 20 commissioners – he wants to streamline decision making and forge an inner core of decision makers.

However, the idea of a two-tier system provoked immediate opposition at a meeting yesterday, where several commissioners warned of the danger of creating internal divisions. Small member states are suspicious, fearing their representatives may be relegated to the second division.

Under the plan, expected to come into force in 2004 before the EU's next expansion, a group of European commissioners will be given an enhanced role and co-ordinate the work of a team of colleagues.

The Commission president will nominate about 10 of his team to be vice-presidents. They will meet once a week and prepare the ground for formal decisions of the whole college of commissioners.

But how the plan works in practice remains to be seen, particularly given the fears expressed by commissioners yesterday that they may be reduced to second-class status.

In response to objections, Mr Prodi floated the idea that the inner core might be rotated, and promised that decisions would be taken "on the basis [of the candidate's] qualities and not on their passport".

Meanwhile, Downing Street upped the ante over calls for a big shake-up at the Seville summit of the workings of the law-making Council of Ministers, where the representatives of the EU governments meet, saying it was vital if the EU was to recover the respect of the voters.

Measures to be put forward by the Spanish presidency, including the televising of some ministerial meetings and the streamlining of committees, are due to be approved at the Seville summit.

The package of measures, which would shorten summits and allow leaders to focus on bigger issues, aims to improve efficiency and help reconnect voters who, the British Government says, are increasingly disgruntled with Europe.

Yesterday, a Downing Street spokesman argued: "The EU has lost touch: far-right politicians have sought to capitalise on apathy about the EU. There is a real danger this will undermine support for Europe's expansion. The Prime Minister sees Seville as an opportunity to show the way we are taking seriously the concerns about legitimacy of the EU." However, several smaller countries are opposing a push to split the General Affairs Council – where EU foreign ministers meet – into two.

At Seville, Mr Prodi will brief EU leaders on his plans to revamp the commission but he has the power to change the team of without the approval of heads of governments.

Most member states recognise change is inevitable with enlargement beckoning. Small countries have been unwilling to give up their right to nominate a commissioner for Brussels, making reform vital to prevent the system seizing up.

Some commissioners have huge workloads and important portfolios while others have very limited powers and responsibilities. Under the Nice Treaty, every country will be entitled to send a commissioner to Brussels until the EU expands to 27 nations – something that cannot happen in the next enlargement in 2004.