When the central bank starts to wind down bond purchases, the high-debt eurozone nations will be at the mercy of global capital markets

ECB now faces an awkward question that it would rather not have to answer: how to justify the continuation of emergency bond purchases once growth is humming and key sectors of the economy hit capacity constraints.

The judges said legality hinges on scale, scope, and how long the one-off scheme lasts. It was a clear hint that the court will not allow the recovery fund to become a trojan horse for permanent fiscal union

This may have potent consequences since global investors are purchasing Italian and Club Med bonds enthusiastically on the loose assumption that the recovery fund is indeed a cloak for a future EU debt union.

Ambrose Evans-Pritchard Telegraph 22 April 2021

https://www.telegraph.co.uk/business/2021/04/22/europes-boom-finally-coming-beware-ecb-sting-tail/

Prof Lucke's case invokes Article 311 of the Treaties.

Ambrose Evans-Pritchard Telegraph 1 April 2021

https://englundmacro.blogspot.com/2021/04/with-750bn-recovery-fund-europes.html