I experienced a similar situation. The team leader looked back at the past few sprints and worked out how many story points we had completed, and calculated how much our salaries had cost the company in that time, to work out a "cost per story point".

He then went off on his own to talk to upper management and committed, without our input, to large new pieces of work, and was told what the budgets for those deliverables were.

At the next sprint planning, he was basically telling developers their estimates were wrong because the number of story points we were deciding equated to more money than the budget for those features.

Rather than play along, I simply said "Well why don't you come up with the estimates for us, then?".

To his credit, he did then stop trying to influence the votes after that, but it wasn't long before the product was put into maintenance mode and he was assigned to a different team.