More than £3.5m was spent on security for MPs in the last financial year, the Independent Parliamentary Standards Authority (IPSA) says.
Although this is less than the £4.5m spent in 2017-18, in total more than £10.6m has been spent on measures since 2016, when the Brexit vote was held.
Just £170,576 was spent on MPs' security in 2015/16.
Since 2016, MPs have raised concerns about threats they have received - including over Brexit.
IPSA said in a report that spending on all budgets was £119.9m, up 2% from £117.3m in 2017-18.
Costs include MPs' offices (£12.4m), staffing (£9.4m), accommodation (£8.9m), travel and subsistence (£5.7m) and disability assistance (£170,000).