OTTAWA -- Federal New Democrats say they would hike the tax on investment profits to pay for pharmacare as well as more affordable childcare and housing.

NDP Leader Jagmeet Singh will lay out his party's proposal to increase taxes on capital gains during a keynote speech today to the Broadbent Institute's Progress Summit in Ottawa.

The plan is expected to form a key plank in the NDP's election platform this fall alongside other policy proposals that the party says will target the rich, pay for more services for Canadians and cool the housing market.

The NDP is specifically looking to tax 75 per cent of profits on investments, up from the current rate of 50 per cent, which it says will raise about $3 billion for the federal treasury.

New Democrats have also talked about closing a stock-option loophole and cracking down on the use of bearer shares and foreign tax havens which they say help the rich avoid paying their fair share of taxes to society.

Some, however, have defended the stock-option loophole as important for attracting talent and encouraging start-ups while numerous governments have promised but largely failed to address tax havens.