In a lawsuit filed Tuesday, Anheuser-Busch is claiming that InBev’s offer of $65 per share for the company represents a “bargain price.”

The offer was made when the market was valuing Busch at about $55. The stock closed on Tuesday at $61.56.

Busch also accused InBev of “deceptive conduct.” The Belgian brewer, according to Busch, lied about having sources of capital lined up for the purchase. There’s no way that any group of lenders “would unconditionally agree to loan InBev the $40 billion it will need,” the suit claims.

That’s true. Once loan amounts hit $30 billion or so, conditions of some kind are usually attached. Busch is worried that such conditions might scotch the deal (if, for example, InBev sees a downturn in business), putting Busch in a worse position.

On Monday, InBev moved to remove all of Busch’s board members, in an attempt to engineer a new board that would approve its bid. Busch’s lawsuit asks for an injunction to stop that effort.

And the trade publication Just Drinks notes an oddity in the lawsuit: Busch noted that InBev has “a significant partnership” with the Cuban government to do business there. “InBev has not commented on how that would impact business with A-B’s customers, nor on its ability to complete an acquisition under U.S.. laws that affect acquisitions of U.S companies by foreign companies.”

A bit of barely disguised red-baiting, perhaps? Is it possible that InBev would gladly dispense with its Cuban business interests, massive though they may be, if that meant it could have Busch? Maybe so. But InBev hasn’t commented on the lawsuit yet.

What’s that line about something being the last refuge of somebody? In any case, pretty much all of the claims in this lawsuit reek of last-ditch desperation. Still, this battle could go on for some time.

UPDATE: The Wall Street Journal’s Deal Journal blog notes that InBev’s Cuban operations amount to just 0.35 percent of the company’s sales.