LONDON — Greece, in the midst of a financial crisis, is planning a bond deal this week that depends on a lot of things going right.

For one, other members of the European Union — much as they would prefer not to — are discussing ways to show that they will stand behind Greece. In recent days, the outlines of a rescue plan have started to come together, probably involving loan guarantees from the German and French governments to encourage their banks to buy Greek debt.

But even as the negotiations continue, the bloc insists that Athens impose further austerity measures, in part to overcome political opposition in Germany to providing aid to what it sees as the spendthrift Greeks.

The markets remain skittish. For weeks, the Greek government, which faces 23 billion euros ($31.3 billion) in debt repayments in April and May, has been testing investors’ diminishing appetite for Greek bonds via a proposed three billion to six billion euro ($4 billion to $8 billion) 10-year offering that it hopes to bring off at an interest rate in the 6 percent range.