European markets rose on Wednesday after a letter from Greek Prime Minister Alexis Tsipras to creditors boosted hopes of a deal on reforms, but analysts warned that investors could be getting ahead of themselves.
Tsipras sent the letter on Tuesday as part of a request for further financial aid, although it only became public on Wednesday.
The Greek leader appeared to offer some concessions on reform plans, but also stuck to his guns on other proposals, such as maintaining a 30 percent discount on the VAT (sales tax) applied to Greek islands which lenders want abolished.
European equities rallied 2 percent on the news, first reported by Financial Times, but analysts were divided on whether the concessions would be enough for a deal with creditors.
Peter Chatwell, an interest rate strategist at Mizuho International, said the letter was "not the climbdown that it seems."
"I strongly doubt Europe will accept this proposal and if Europe sticks to its guns and waits for the referendum, the greater the chance that the government fails," he said in a note.
While Carsten Brezski, senior economist at ING, told CNBC the letter was "another tactical move to stay ahead of the euro zone in the ongoing blame game, rather than a serious change of mind."
"In my view, the euro zone will not move any more ahead of the referendum," he added.