Marks & Spencer has rejected an increased offer for the company from retail entrepreneur Philip Green.
Philip Green has had M&S in his sights for some time
Mr Green upped his bid to 370p - worth around £8.14bn - after a bid of between 290p and 310p was turned down earlier this month.
But M&S said the offer "significantly undervalues" the group, adding it would not be recommended to shareholders.
Widely seen as a national institution, M&S has suffered a decline in sales since the late 1990s.
Shares in the company were trading at 354p at 0945 on Thursday, down from 363p at the beginning of the day.
Mr Green made his fresh offer after holding talks with the retail giant's chairman and chief executive.
Under the new deal - through his bid vehicle Revival Acquisitions - Mr Green offered M&S shareholders a choice of either a straight cash offer of 370p for each share, or a partial share alternative.
Under the original bid the billionaire had offered £7bn and a 25% stake in his bid vehicle.
'Not for sale'
Earlier, shares in M&S surged 3% amid swirling market speculation that Mr Green was about to make an improved offer for the group.
They ended Wednesday's session 6.5p higher at 363.5p.
M&S chief executive Stuart Rose confirmed that the board had met Mr Green earlier and then had later discussed his offer.
He added that his current review of the group was
progressing well and vowed to set out plans on July 12 to improve its operating performance.
M&S chairman Paul Myners also weighed into the battle
telling reporters: "This business is not for sale."
He added that the proposed offer "simply isn't of a level we can possibly recommend."
Mr Green's latest offer still falls short of the 400p a share, or £9bn that many shareholders had wanted.
One such shareholder - Bob Parker, deputy chairman of Credit Suisse Asset Management - said that while there were positives to Mr Green's new improved offer, many negatives still remained.
"The main positive is that this is an all-cash offer and a significant premium over the first proposal." he said.
"However, negatives remain. Firstly there is uncertainty over the potential intervention of competition authorities, and secondly has been a lot of opinion in the city that a successful offer would have to be close to, or above £4 a share, and we are still not near that.
"Finally a lot of financial institutions have been very impressed by the changes of management at M&S and what Stuart Rose is putting in place."
Mr Green, who owns BhS and Arcadia clothing stores, has made no secret of his determination to take over the high street name - even to the point of putting £1bn of his own money into financing the offer.
In recent years M&S has suffered from flagging sales - despite efforts to improve its image with new "concept" stores and by bringing in popular fashion designers to improve its old-fashioned clothing image.
Last month it revealed sales had fallen in the face of fierce competition from rivals like Next and cheaper clothing in supermarket chains such as Tesco and Asda.
In an effort to fend off Mr Green's overtures it brought in Stuart Rose - the former chief executive of Mr Green's Arcadia Group.
Mr Rose quit the group two years ago when Mr Green took it over.