EUOBSERVER / BRUSSELS - Updated 17.00 CET European commission president Jose Manuel Barroso is in the process of organising a mini-summit brainstorming on a new-look EU constitution with the aim of giving "momentum" to the ongoing talks on the future treaty. The informal meeting is to take place next month, soon after the second round of the French elections with 12-13 May being slated as the date. Exactly who will be coming remains unclear, with only a select number of EU leaders expected to be invited. Dutch newspaper Volkskrant reports that Dutch leader Jan Peter Balkenende has already been invited and that German chancellor Angela Merkel and Portuguese prime minister Jose Socrates are also set to attend. Sources have told EUobserver the upcoming EU presidencies until 2009 - the end of Mr Barroso's current mandate - have been invited.