stumbling block

The stumbling block is the UK government has made it clear, including in its manifesto, that it is opposed to another referendum.

If, as has been reported, Thelwell and Stewart were the stumbling block then the obvious solution is to sack that pair and invite Gerrard back for more talks.

A dearth of public charging stations was long considered a stumbling block for persuading more drivers to embrace EVs.

Even if the talks stay focused on logistics, there could be stumbling blocks.

Trying to find precise language that will fill in the gaps will provide plenty of potential stumbling blocks.