Originally Posted by
GS
They may want to, but they have no intrinsic right to. Ultimately the governing party is effectively bound by their manifesto.
The Salisbury Convention dictates that the Lords won't block anything that was included in the manifesto, but if it wasn't then they are free to do so. It's why May wouldn't get grammar schools through in this parliament without a fresh mandate.
Hammond wanted to increase NIC, and couldn't because of the outcry over a manifesto breach. Changing PM doesn't change any of this, so it's not a relevant trigger for a new election. People voted for a party, and their programme for government. The leader is irrelevant.
On a side note, the Liberal "Democrats" are on record as saying they won't abide by the Salisbury Convention any more. Effectively they're using their Lords in lieu of being roasted in the general election. When you consider that in the context of their clear policy breach on tuition fees, and their Brexit stance, they're probably the most anti democratic party in the UK.