The Bradford based company has been nudging the bottom of the table for the last 12 months and just managed to dodge relegation in the last reshuffle.
Its share price has fallen by 13 per cent to 151.30p over the last 12 months, giving the supermarket a market capitalisation of £3.53bn.
It currently stands as the 111th in value terms on the London stock market.
Chief executive David Potts, taking the reigns from Dalton Philips earlier this year, has axed jobs at the firm's headquarters and cut costs elsewhere to try and slow the tumbling share price.
Earlier today FTSE Russell, that manages the indexes and is owned by the London Stock Exchange Group, warned Morrisons was in danger of exiting the top tier index.
Worldpay, the payments firm that recently listed in London, financial services group Provident Financial, and Irish services firm DCC are reportedly going to be bumped up to the FTSE 100.
The share price of the firm is used to decide whether they’ll be included in the index, with a valued in the top 90 UK companies required for admittance.
If a company's value falls outside of the top 110 then they face being relegated.
The decision was first reported by business news site thebusinessdesk.com.