According to Marca, senior figures at the Bernabéu have told the Brazilian's representatives that the current proposal is their last, with no further increase or additional round of negotiations on the table.
The move comes after Arsenal's interest in the forward became public last weekend, with the Gunners having made contact over a player who has just a year left on his contract.
Should Vinicius turn down Madrid's offer, the club intends to open the door to a sale this summer rather than risk him running down his deal and leaving for nothing next year. Vinicius has previously voiced his commitment to Real Madrid and had been in a lengthy standoff over terms even before Arsenal's interest emerged, with reported figures on both sides — his wage demands and Madrid's ceiling — remaining far apart for much of the past year.
Arsenal have shown they are prepared to spend at the top end of the market this summer, having already added Christos Tzolis from Club Brugge for £34m. Manager Mikel Arteta, speaking from the club's warm-weather training camp in Spain, made clear the scale of his ambition following last season's Champions League final defeat to PSG.
"This has to be the start and this has to be the standard. Excellence has to be our standard and this has to drive us to attack the future," he said. "The way we behave daily with more and more determination and ambition because we've shown that we've got it.
"Now we have to show that we belong to this level and we want to increase and take this football club to a different dimension."
Arteta went further on the scale of investment required, addressing the club's transfer strategy directly.
"We all know about the context of this transfer window. From ownership to the board, the sporting director and myself, we know that we want to take this club to a different level," he said. "That is going to require a better squad, better individuals.
"We have identified where we have opportunities to grow and to improve and to evolve our game and what is going to be needed to achieve that. Hopefully very soon we can start to put things in a very concrete way."