Everton are said to be Hackney's preferred choice this summer but the Toffees are still short of Boro's valuation of the 23-year-old. Everton's second offer is believed to have been a package worth around £15m.
But Boro received bids around the £20m mark 12 months ago, and although Hackney is now closer to becoming a free agent - his contract expires next summer - his stock has risen over the course of the last year. He was named the Championship's Player of the Season.
There's also more firm interest than there was 12 months ago. Now, at least half a dozen Premier League clubs are keen on Hackney and closely monitoring developments.
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Fresh reports on Monday night claimed Palace, long known to be admirers of Hackney, are now preparing a bid of their own. It's said the UEFA Conference League winners are expected to offer a package worth around £20m.
Hull City are another club interested but a move to the newly promoted Tigers is unlikely to be of interest to Hackney given some of the other clubs who are keen.
Manchester United are one of them, with Michael Carrick a huge fan of Hackney, who emerged as a star at the Riverside under the watch of the former England midfielder.
Nottingham Forest had a bid for Hackney rejected late in the January window and are likely to be in a position where they'll have to replace Elliot Anderson this summer, with Manchester City pushing to sign the former Newcastle man. Tottenham, Fulham and Brentford are threeother clubs monitoring Hackney's situation.
Everton were first to act this summer but, as reported by the Northern Echo last week, the Toffees were way short of Boro's asking price with their initial approach at the end of last week and still have some way to go if they wish to strike a deal. Boro will stand firm and are willing to keep Hackney, despite his contract status, if their valuation isn't met.
Everton's hand might be forced if other clubs step up their pursuit of Hackney, which is what Palace are said to be preparing to do.
Palace would be able to offer Hackney European football, though it's not yet known who will be in charge next season after Oliver Glasner's exit. The Eagles have held talks with Lens manager Pierre Sage.