Complex sentence: Questions were raised in Parliament about the safety of tunnelling so close to the vaults of many City banks and the risk that subsidence might cause vault doors to jam shut or undermine the foundations of the Dutch Church in Austin Friars.
Split into simpler sentences: Questions were raised in Parliament about the safety of tunnelling so close to the vaults of many City banks and the risk that subsidence might cause vault doors to jam shut. Another concern was the danger of undermining the foundations of the Dutch Church in Austin Friars.