ECB has shown flagship stimulus plan is proportional - Finance Minister Scholz

BERLIN (Reuters) - The European Central Bank has honoured the principle of proportionality with its flagship stimulus programme, German Finance Minister Olaf Scholz said in a letter to the president of Germany's lower house of parliament.Germany's top court last month gave the ECB three months to justify bond purchases under the stimulus plan - the Public Sector Purchase Programme (PSPP) - or lose the Bundesbank as a participant.In the June 26 letter, a copy of which was seen by Reuters, Scholz..